If you want a bargain, try e-bay. Look for used GTX460 cards. Lots of graphics cards are showing up as people are marketing them to raise funds for the GTX580 for the anticipated 6970 and GTX570 cards. Look at completed listings to see what cards are actually selling for.
If ebay is not your thing, then now is OK. Get what you want, and don't anguish over small price differences.
I suggest you consider upgrading a couple of tiers to a GTX470 or GTX480. A GTX460 is a relatively small jump and you will be disappointed if you don't see a lot of improvement.