I've noticed that collected editions are never more than retail price at my local comic shops, no matter how high the market value might be at the time.
Maybe they can't be bothered keeping track of temporary fluctuations in the market. It seems to be more of an online thing.

Curiously, the Doctor Strange Masterworks SC vol 1 that I traded away many months ago was still sitting on the shelf for normal price at my LCS on Saturday.