Take a look at allelectronics.com. I bought some motors from them before I got my Sully system, and their prices are cheap. I think that they have a 30 RPM gear motor for around $3 or so. They have a bigger one for around $12 that is also 30 RPM. They worked fine for me, and since I'm an electronics idiot, it didn't hurt so bad if I wired my things wrong and smoked one.

------------------