Some people are really detail oriented.

Let's assume we're working with a $700 budget, at least a third of which is in the form of gift cards.

Judging by bestbuy.com I think you're over on some of your estimates, particularly when the in-store cost (I've found) is cheaper than the online price (I figure they build shipping costs in).

The PS3 appears to be the most expensive of the options listed in the original post.