Why? You assume the shop got a deal on them. Maybe they bought from Specialized at full price only to have Specialized discount them later. Happens all the time.

No. It's the shop's choice of whether to mark them down and take a hit. Frankly, if it were me and they were selling well in my store, I'd leave them be. It costs money to have someone change all the info in the POS and retag the stuff. You found a deal online? Great. Go for it. You're willing to wait a few days to save a few bucks. Fine.

If on the other hand, I bought 50 of them in July and there are 40 left in October, obviously it wasn't a very desirable product to begin with. If I were to see the distributor selling to the public at a discounted price, I'd either send the product back for a full credit, or ask for a credit in line with their discount and mark 'em down and hope they sell.