Chinese mesotheles: segmented abdomens, plate-marked backs, and a body plan that predates nearly everything else in the hobby by hundreds of millions of years. Keeping one is keeping a lineage, not a display.
They dig silk-lined burrows with hinged doors and live at the hinge, permanently. Mesotheles lack functional venom glands, so the venom question that structures every other spider entry here simply does not apply. The door is the show.
Chinese origin with no export trade and a captive population near a rounding error: listings are sparse, single-seller, and priced to the tiny audience for whom deep time is the product. The genus trades on what it is, because you will almost never see what it does.