Buy Apple shares as in... to invest?
Or you just want a single share of stock to put in a frame?
I'm guessing it's the latter - if so, then frameastock.com is a bit cheaper I think, since I don't know if you have to buy the frame. And if you do have to buy, the frames there are cheaper.
If it's the former, then you're looking at ameritrade, scottrader, etc.