or i could get a i5 3570 for 202 dollars
True, you expressly stated overclocking was a big deal for you multiple times. You didn't seem opposed to the idea of swapping out your motherboard. The 3570 is at 202 and the 3570K is at 215, being able to overclock some time in the future seems like a good deal for only 13 bucks more.
Edit: ah you edited your post, I never buy used parts and certainly not for a measly 10 dollars off the cost a new part.