Depends on the barrel length you want. If it is a 10.3-10.5", then get DD. It's at the upper range of the mid-end AR's and many people are quite happy with them. If you want something with a barrel between 10.5" and 14.5", you'll need to increase your budget some. 14.5" and up can be had for around $600 and up (starting with the Chinese guns, and yes you could get a 10.5" Chinese AR too). Personally I'd look at DD, Stag Arms for mid-tier rifles, or KAC, LMT and Noveske for the higher end ones. All available from sponsors here.
PS- Don't forget to budget for optics! Very important to get decent optics, buy once cry once.