$150 for the board, maybe $200 for the chip...
I don't see the cost issue here, on a decent board (since you don't need a great one as all the overclocking is chip based) you're looking to spend like $60.
You will find the core vs core performance as well as overclocking head room will help reduce any bottleneck you may currently be experiencing.
Here is my vantage run. On my 1090T (which is nothing like a i7-920) I saw up to a 30% bottleneck on the testing from it being single threaded.
While 0% bottleneck is awesome, the most epic part about is was the fact that the core getting used the most only went up to 63% usage (whereas my 1090T hit 100%, then I saw gpu usage drop to 70%).
Which means not only is it fast enough to not bottleneck at all, you've got room, about 40% more cpu power than my gtx 470 can use single threaded.Edited by BallaTheFeared - 1/13/11 at 11:59am