In order for people to find this thread more easily, I'm including some key words, of some of the more popular buys on the used market [probably missed a few]:
TASCAM 22-2, TASCAM 22-4, TASCAM 32, TASCAM 34, TASCAM 34B, TASCAM 38, TASCAM 48, TASCAM 58, TASCAM 388, TASCAM TSR-8, TASCAM M30, TASCAM M308, TASCAM M308B, TASCAM M312, TASCAM M312B, TASCAM M320, TASCAM M320B, TEAC A-3440, TEAC 80-8.