I currently have i3 2100 and planning to upgrade so my dilemma is to buy a brand new i7 3770? or used i7 3770. is it safe to buy a used i7 3770? I choose the non k so I'm confident it's not abused because it's not overclocked and also my mobo MSI H61M does not fully support overclocking. So my second choice is to buy a brand new i5 and buy a new mobo too. my budget is only $300 so can you suggest more options? or can you help me with my options?