For the Gamestops here, if they already have a lot of copies of the game you bring up they give you a case that already has the disc in it (they store all the discs in a case already so it's faster than looking for a case and putting the disc in the one you bring up I guess..) I always have to watch the cashier in case that happens because it can be a hit or miss on whether the copy they bring up is a greatest hits / missing manual.
Yup, this happened to me last night. I've been looking for the Platinum Hits edition of Mass Effect, since it comes w/ a bonus disc containing the Bring Down the Sky DLC. I found the PH case at Gamestop, and brought it up to the cashier. One guy goes behind the counter and brings out a regular non-PH edition of Mass Effect and is about to ring it up.
I said "Um, I specifically want the Platinum Hits version since it comes w/ 2 discs."
The cashier says "Oh, I don't think Mass Effect 1 comes with a 2nd disc, only Mass Effect 2 does, but I'll go look."
Sure enough they find the PH version, but it's in a black case as opposed to the platinum grey case I found on the shelf. Then I needed to say "Could I get THIS case from the shelf instead?"