Cheapest possible CPU for flashing Z170 gaming M5 motherboard?

Dylan_43

Commendable
Mar 10, 2016
47
0
1,530
I need to flash a Z170 gaming M5 motherboard so its compatible for my new I7700 CPU, what is the cheapest possible CPU that will work on this motherboard?
 
He can't return a used CPU back to the seller on EBAY when he is done flashing. I mean he could but it is a jerk move considering the sellers often don't have bulk shipping rates.

I'd just go to Frys, buy a 3900, and then return it. Worst case scenario is a 15% restocking fee - or like 8 bucks.