Transmission Question

[Drewe30e]

Well the transmission is now making some interesting noises. :x So, I've decided to just get a new transmission. I have recieved a few offers for used transmissions off of some forums that don't seem too bad. However, a lot of them either have high mileage or no known mileage at all. Everyone on the forums say that these trannies (Getrag 260) are solid and never go bad unless they get low on fluid. Guess how mine was destroyed (I'm a neglegent ass)?

Anyways, does anyone know anything about e30 trannies? What mileage is good, prices for a used one, and what I should look for?