Need upgrade help MoBO/CPU/RAM

So, after much drama and time spent with techs for diagnostic, it appears my motherboard is dead. I understand that if I'm replacing MoBo, I should also probably replace CPU and RAM since they're all the same age, but I have no idea what's reasonable here.

Current specs as follows:

ASUS P5N-D Motherboard,
Intel Core 2 Quad Q9300 Processor,
Sapphire R7 260X 2GB GDDR5 OC,
DiabloTek PHD650 ATX Power Supply,
Corsair XMS2 TWIN4X4096-6400C5C 8GB Memory,
Windows 7 64-bit

I really don't have a ton of cash to spend, but I'd like to play WoW and Skyrim and Diablo III with decent framerate.

Halp please?