FangTrack is a market intelligence platform for the exotic invertebrate hobby — the first product to bring Keepa-style price history, StockX-style deal scoring, and TCG-inspired rarity tracking to the tarantula, scorpion, centipede, and isopod market.
Transparency on rarity, availability, and price is not a one-sided win for buyers. Breeders and sellers currently price by instinct, forum osmosis, and whatever the last Facebook sale rumored to close at. FangTrack gives the supply side the same market data the demand side sees: what a specimen of that species, size class, sex, and source type actually trades for right now. A breeder holding a rare sac can price with confidence instead of guessing. A seller moving common stock can deliberately price under market to turn inventory fast, at market to hold margin, or over market when scarcity justifies it. Markets with visible prices do not shrink seller profits; they reward the sellers who understand them.
The current product is a local web application that crawls78 US vendors, scores 6,882 live listings per crawl against historical price records, and surfaces deal alerts to a collector's watchlist. Phase 2 is a hosted consumer product. Phase 3 is a marketplace intelligence layer comparable to MorphMarket but focused on price transparency rather than transaction facilitation.
A quick tour of every tab and what it does.
FangTrack scrapes 78 invertebrate vendors, pulls every live listing, and compares each one against the whole market and its own price history. It then tags each listing with a deal rating so you can see, at a glance, what's genuinely a good value versus what's overpriced. Add species you want to a Watchlist and FangTrack tells you the moment one shows up at your target price.
The data refreshes automatically on a schedule — you don't run anything. Just open Deals to see the latest, or add species to your Watchlist to be alerted.
| 🔥 | Fire deal — the lowest delivered price (item + shipping) ever seen for that species, sex and size class, and only when at least two vendors compete on it. The rarest, strongest signal. |
| 💎💎 | Exceptional — at least 40% below the market median for a like-for-like comparison (same species, sex, size), or 20% below and also an all-time low. |
| 💎 | Strong — 20–40% below market median. |
| 👍 | Fair — within ~10% of market. Also where listings land when size is unknown (we can't confirm a real discount, so we don't overclaim one). |
| 👎 | Above market — priced meaningfully higher than comparable listings. |
Ratings are always like-for-like: a listing is only compared with the same species, the same sex group (female / male / mature male / unsexed are kept separate), and the same size class. Captive-bred, wild-caught, and unstated-source listings all compete together — most vendors never state a source, so excluding them would knock the majority of honest listings out of contention. We show the CB / WC / ? tag on every listing as information, but it carries no weight in the score. Always confirm the source with the seller and choose captive-bred (CB) whenever possible.
A separate signal from deals. Every species is percentile-ranked across the whole tracked catalog by how few sellers carry it — rarest at the top. The named tier answers "how hard is this to find right now?"
| Mythic | Grail tier — the rarest ~5% of species. Lucky to see it listed at all. |
| Legendary | Very hard to find — only a handful of sellers ever carry it. |
| Rare | A few sellers stock it, and it tends to sell fast. |
| Uncommon | You'll shop a few sellers to find one. |
| Common | Widely carried across the market. |
| Ubiquitous | Everywhere, almost always in stock. |
The tiles across the top are live counts from the most recent crawl of the vendor websites only — private-seller lists are never counted here. Every tile is clickable and opens the Deals page pre-filtered to it.
| Total listings | Every in-stock listing across the sites we crawl. This is the pool everything else is scored against. |
| 🔥 Fire deals | Listings at the lowest delivered price (item + shipping) ever recorded for that species/sex/size — and only where at least two vendors compete. The strongest signal. |
| 💎💎 Exceptional | At least 40% below the like-for-like market median, or 20% below and also an all-time low. |
| 💎 Strong | 20–40% below median. |
| 👍 Fair | Within ~10% of market — a normal price. Also where a listing lands when its size isn't stated (we won't claim a discount we can't verify). |
| 👎 Above market | Priced meaningfully higher than comparable listings. |
| ♀ Females | Listings sold as sexed females — usually the premium a keeper pays to skip the maturity gamble. |
| 🎯 Watchlist | How many of your tracked species had a hit in the latest crawl. |
The Top Deals list below the tiles is the market's best offers right now: every 🔥 Fire and 💎💎 Exceptional listing, shown by lowest ask first. If it's on that list, it's either an all-time-low delivered price or at least 40% under the median — never just "inexpensive." As always, confirm the price and source on the vendor's own site before buying.
Rarity (x/10) — how uncommon a species (and size class) is across the tracked market. Higher = fewer sellers carry it.
CB / WC — captive-bred vs. wild-caught, inferred from the listing. They're never price-compared to each other.
Each species page shows up to six at-a-glance badges — the husbandry and safety facts a buyer asks first. They're researched per species (genus defaults with species-level corrections), and always appear in the same order. Hover any badge for the detail.
These are general guidance from reputable care sheets, not a substitute for researching your specific animal — always confirm care with the seller and a trusted source before buying. Scorpions and jumping spiders show a trimmed set suited to them.
Everything FangTrack sees is an asking price, not a completed sale — no vendor tells us what an animal finally sold for. So the market price for a species is the trimmed median of recent asks: we sort them, drop the single highest and single lowest, and take the middle of what remains. One eye-watering listing therefore cannot drag the number up, and one clearance sling cannot drag it down. Where we have fewer than four asks to work with there is nothing safe to trim, so it is the plain median of what we have.
A small number of sellers are excluded from the price statistics. Some shops deal mainly in premium display specimens — hand-picked adult females, communal groups, animals sold with a full enclosure — and their asks routinely run several times what the same species goes for elsewhere. Those are real listings and real animals, but they describe a different product, so letting them into the median would publish a price almost nobody is actually paying. On a species where such a shop is the only seller, its ask would simply become the market price.
So their listings still appear on the species page and in Deals, with a link straight to the seller — we are not hiding anyone, and if that specimen is what you want, you should be able to find and buy it. They are only kept out of the calculated figures: market price, lowest ask, all-time low, the 90-day range, and the movers and records on the dashboard. That is why a species page can show more listings in its table than the count in the stat cards above it, and the table says so when it happens.
It is a short, reviewed list rather than an automatic rule. We identify candidates by comparing a seller's asks against the market price for the same species across every other vendor: a normal shop sits at roughly 1× the market, and the excluded ones sit at 3× or more with a large share of listings above 8×. Being excluded is not a judgement about a seller’s honesty or their animals — it means their prices answer a different question than the one this number is trying to answer.
Tarantula prices swing enormously with sex and size — a confirmed adult female can be worth 3–6× an unsexed sling of the same species. So FangTrack values every animal in your collection like-for-like instead of using one blended average:
Worked example. A Green Bottle Blue: as an unsexed 1" sling it's worth about $60 (what slings actually list for); as a confirmed adult female it's valued near $250, because that's the median of the adult-female GBBs listed right now — not the ~$85 you'd get by averaging every GBB of every size and sex together.
It's a market estimate from live asking prices, not a formal appraisal or a guaranteed sale price — the more precisely you record each animal's sex and size, the sharper the estimate. Purchase prices you enter stay private to you.
Short answer: we don't.
FangTrack is a hobby project that currently costs about $80 a month to run, on a projected pace of about $100 a month by the end of 2026.
No ads. No affiliate links. No fees from sellers. Every listing links straight to the vendor, and we take nothing when you buy.
Donations to the cause are welcome, but not required.