Flippais more to Websites, I suggest sedo, webmaster forums, expiring domain markets like at Godaddy, name.com, dynadot and moniker etc
for that budget I don't think so you'll get domain at SEDO, Namepros, etc better try some domain selling forums.
If you want an aged domain which is 4 years old,try searching on Godaddy auctions or you cna also get at Namepros and Digitalpoint