How cheap? I have an early 90s 4-channel Yamaha amp I might be willing to part with. 50 watts per channel, built-in 12 dB/octave variable crossover. Can be bridged/configured to 50w x 2 + 100w x 1, or 100w x 2. Has a built-in cooling fan. I believe it was built by Alpine, as it physically resembles them and the connection terminals look identical to what Alpine's did back then. I've had absolutely no problems with it in our south Texas heat (but then I don't listen at insane volumes or try to run 2-ohm loads). Hasn't been used since I think about 2000 or 2001.