You can get a Nexus 4 for a good price, I think somewhere around $250 and thats brand new. Unlocked and everything. Nexus 4 - Google
Only hard part is getting it while they are in stock.
I have a Galaxy Nexus and love the phone, battery life kinda sucks but you should be able to get them cheap now that they are kinda being replaced by the other newer phones. Its a great phone if you like to tinker with your phone and put new roms and such on them.