Welcome to the forum!
I think that there are a number of receivers that will fit your budget and desire for HDMI audio processing. Some examples are the Yamaha RX-V465 and RX-V565 (if on sale), and the Onkyo 507. There are surely others, but those are ones that I can think of at the moment.
The Audioholics Store is having a sale on receivers right now. I don't know the prices, but you can call them at 1-877-246-5427 to get the latest prices. I like Amazon, too, and they have good prices sometimes.
I'm not as impressed with this year's crop of receivers as I was with last year's. Companies are removing some flexibility from the low to mid-level recievers (such as assignable inputs, which I really like). The Yamaha RX-V663, which is a nice unit and a very popular one from last year, is being sold by a reputable member here for $325 at the link
here. I know that you are new and don't know Phil, so I'm not pushing that on you - just wanted to let you know.