even if you get a e8500 you wont notice much of a boost .. heck even my old q9650 which was supposed to be best(not including the core2extreme that i have yet to witness IRL) of the old class isnt doing all that great anymore.. I'm just waiting for AMDs ZEN to be released and ill swap it all.. ive got an old hd 7950 3gb GPU and its heavily bottlenecked by my q9650 which is best you could get now.. not to mention.. PCs arent meant to last forever.. that comes VERY true around mobos.. my old p43 is dying slowly and getting a new one is impossible now.. you can test your luck on used ones but its like a coin toss.. either you get one that will last you a year.. or you get one that will die on you in next month or so..
in all honesty...