Does "core clock speed" matter on these 8800GTSes?

[cmccomas]

Ok, this is confusing.
So here are 3 8800GTS 640MB cards with the only diff I see being the clock speed. Can I just overclock the lower card to the higher card clock setting and save myself the money? What's the real difference between these, just the clock setting? Can't that be easily changed? (if so, are folks just paying to save themselves the hassle of OC-ing?)

Thanks as always for the excellent responses.

 

[xSkyDrAx]

get the cheapest one. OC if you feel it necessary to do so. I've been playing games w/ my 8800 GTS @ 1680x1050 stock and I've have no troubles w/ any of the games I've thrown at it on max settings.

 

[lavaheadache]

factory oc's are modest at best and almost any card you get will clock to that level. buy a card from a company like evga and your warranty covers overclocking.

 

[cmccomas]

Perfect, thanks for the help guys. I snagged the lower clock one.