Your best bet at that price will probably be ebay. Im currently using a Farenheit CLX940-2 that I got new with no warrenty on ebay for about $120. Its a class X and puts out about 700-800 watts rms @ 2ohms. I ended up buing 6 more of those amps for friends and family, never had a problem any of them. Im working on a rack for my amp and Im gonna change out the Profile for a Farenheit 4 ch amp.
A 800 watt Profile California amp will probably cost that much on ebay also.
Your best bet would probably be either a Profile or something from Lanzar or Poweracoutik. I would be weary of the poweracoutiks though, dont hear much about them.
there is the Soundstream 880.1 and I cant find wher it is on sale but a few people on here recently bought the amp and love it, serious power for the money