recommendations on where to buy CS4? I’ve looked on Amazon and a couple other places and the prices seem to vary so much? prices are anywhere b/w $180-$500. why is that?
The only way you can get a copy of CS4 is second hand and then you would run the possible risk of activation (duplicate installs), getting an illegal import copy (which won’t activate) or a pirated / cracked version, or even an academic / upgrade version advertised as otherwise. Don’t bother running the risk, it’s not worth risking your money on anything that seems too good to be true (or from an un-established reseller), if it’s more than 10% cheaper, it’s probably a fake. 
I doubt prices for the genuine article would vary much, so beware of pirated copies. Large differences might also be due to education vs professional prices.
Just be glad you are buying from within the USA, as prices are vastly higher for us poor souls overseas, who have to pay vastly inflated prices! :mad:
PS
You do realize that CS5 is out now, I presume?