Well, with a used tranny, you're taking a chance. These cars are up in age, no telling what might be wrong. I have heard quotes of $3000 to $4000, so the price for rebuilding doesn't sound so bad. I believe swapping a manual can be cheaper. There are people who have done this swap, they can give more info. There's not a lot of choices in trannys. Two 4 speeds and one 5 speed. And I don't believe they will interchange. Are you planning on keeping it for a while? If you are, rebuild the auto or swap in a manual. If not, used tranny and a "for sale" sign.
1995 325I, tinted windows, K&N, debaffled air box, BMW style #104 wheels, Nighthawk low beams, smoked side markers, smoked corners, smoked taillights, M3 style heated mirrors, various interior bits, Bosal cat-back