XFX 5850 Black Edition with an i5 750 OC to 4Ghz Replacement

Hey All...

My gaming rig is about 2 years old with the system specs as follows:

MB: Asus P7P55D Pro
CPU: Intel i5 750 OC to 4ghz
Video Card: XFX 5850 Black Edition
RAM: 8gb
PS: 750 Watt Corsair
Case: NZXT Tempest Evo
Cooling: Air
Temps: Around 38-40c at stock and around 55-60 at load
OS: Windows 7

Recently my Video Card has started making a loud noise with the fan at start up which sounds like its starting to die...It eventually levels out but its worrying.

Whats my best bet for an upgrade or replacement in the $250 - $350 range? My current games are EQ2 (i know thats CPU intensive vs GPU) and BF3. I also play some Skyrim and Diablo III