can't think of any real issues Evos have that aren't directly linked to abuse. the STi has an infinitely stronger transmission but that's about it, with 2-3k invested in an Evo you're firmly in the 400whp range (reliably).
im going to guess it's because it's a non SMG? i haven't found too many for sale yet with a traditional 6 speed, but also haven't been looking aggressively.
i can do general maintenance such as brakes and fluid changes, so that aside how potentially disastrous is it to own that car (financially)?