Comparing 3GS phone availability between Apple and ATT its clear that Apple has more and seems to get more regular delivery of stock. How does Best Buy compare? Are they in the same predicament as ATT; currently only taking orders for 3GS?
There is no real way to tell since Best Buy will only let you check availability in store, my imagination tells me that they got less phones then AT&T.
If you have a choice, I wouldn't even bother with Best Buy. If you're lucky enough to get them to answer their phone, then it's not a bad idea to try. However, unless you live across the street, I certainly wouldn't go there blind hoping to get lucky.