13thmonkey :
if you can get the k up to say 4.3, it'll be 25% faster than the non k. Now most games won't use that yet, but when that extra 25% comes in handy (and on some games it will) it'll be worth a lot more than $30.
You haven't taken into account the extra cost of a Z97 mobo over a H97 and a CPU cooler, though.
But you are right. That's the reason I decided to spend all the extra money, for future proofing.
"so I can't do any sort of overclocking with a h97 motherboard, will the 4690 overclock on a z97 motherbpard and will the 4690K only work on the Z97 motherboard and vice versa"
You can't overclock a 4690 at all, even on a Z97 board.
You also cannot overclock a 4690K on a H97 board.