search amazon or other sellers for lower end denons and onkyos, you can find plenty of models from the last couple of years going for under $300. granted most of the lower models only have audyssey 2eq or basic multeq, but still audyssey tech none the less.
here is just one example:
Lower end models of Denons, at least, won't have pre-outs, which is one of the stated requirements. He'd have to step up to the 3312ci (or 3313ci for the current model) for that feature.
ahh, i didnt catch the preouts being a requirement...
the cheapest receiver with audyssey and preouts that I am aware of. would be last years onkyo 709 and 809. both can be found (if you catch the sale at the right time) for under $500.