If you can live without HDMI for the time being, you can get an insane deal on a refurbed Yamaha RX-V659 (less than $300, sometimes less than $250!). There's a review with measurements on this site. This one has an impressively-robust power amp section, and for the prices it can be had for, it's a killer deal. It even has phono inputs and a preamp output for all channels.
A B-stock RX-V661 can be had for your budget as well, and it has HDMI. A little less power than the 659, but retains the phono pre and full preouts. I've seen them pop up on ubid.com for around $300.
Todd in Cheesecurdistan