skurn,
I see what you're saying; but what I am saying is simply different. My point, at least for now, is that I have seen the same supply being available both at the store and online, however that is true only for the Apple configured machines. If you want a superdrive in your Dual 1.25 you simply cannot get it at the store, and it can be ordered online. Now notice that the Superdrive is one of Apple's recurring selling point. Were it available at the store one would be seating on my desk now. For that matter I would get a 1.42Mhz, which Apple configures with the Superdrive, however those won't be available for at least another month.
Anyway, I really doubt there there is ever any difference in availability between the stores and online, except for display/demo models.
gio