300w PSU, you will have to buy a new one of those too. so add that into your costs. You will need at least a 500w PSU. That is also a pretty crappy motherboard not sure you can even use it to OC the i5 3570k. Sure it will cost you less but to get it up to what you want you will need to replace almost all the parts other than the CPU lol... It also only has 1333 ram and 500gb HDD... you could get better parts for the same price if you built your own.