Small to moderate South American terrestrials, and E. campestratus, the pink zebra beauty, has one of the better temperaments in the entire hobby.
Slow, calm, terrestrial, reluctant to kick hair, and forgiving of husbandry that would kill something more demanding. It competes directly with the curly hair and the chaco golden knee for a first-tarantula recommendation and holds up against both.
The growth rate is glacial, which is the whole price structure: slings sell for a fraction of an adult because they are years from anything impressive, and mature females carry a heavy premium because producing one takes most of a decade. Paraguayan and Argentine captive lines supply the market steadily. There is no scarcity story here and there has not been one for a long time.