Do they sell video cards/ graphics cards in this best buy store for desktop pcs/ towers

I don't believe so. They don't really sell PC components. Just the PC as a whole.

Yes but they dont have a very large selection

Yep but like everyone said kind of a small selection

Yes they do.

Yes, they do. Hope you're not liking for a particular one. Small selection.

Yes they currently do for a little while only