Which carrier are you with (wondering which 3G bands you require)?
Best bang for buck I have seen (never used it since it isn't available in the States) has to be the Orange San Francisco because it has a 3.5" AMOLED WVGA display.
You might be able to find my phone, an Acer Liquid in that price range (if you are lucky). Liquid is a good phone. 3.5" WVGA display, 5MP camera, 768MHz Snapdragon (same Snapdragon as Nexus One just slightly underclocked), Android 2.1 officially (but very easy to put Android 2.2 on there). Only real downfall is the fact that it has 256MB of RAM (tho on 2.1 that was never really a problem for me).