If you want cheap cheap, You'll have to go to Ebay.
Personally, I stay away from the consumer electronics section and do the Musical Instruments> Pro Audio> Power Amplifiers section. It seems like you can get more watts per $, with similar distortion. IMHO Prosumer > Consumer.
Your milage may vary. Read up on the amp before you buy 1. Also, you could make a post in the amp's section of the msgboard. There are always good suggestions there.
My preferred brands are Carver, Crown, Yamaha, and Ashly.
Reorx