I don't know what you're needing a monoblock to power but if you can handle (or rather your substage can handle) more than 1,000w there is a Diamond Audio D61500.1 for sale here on the forum for $265/shipped.
Rated for 1500w @ 1 Ohm I haven't seen one yet (including the one I run) that won't exceed that rating to some degree. Under $300/shipped for that kind of power (and a quality brand name - no Boss, Pyle, Or Legacy gear there...) is a tough-to-beat deal. //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif
Have a look through the Classifieds if interested. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif