These LGS's are fucking up the whole reason that WotC did this

WotC isn't going to go after stores for charging $5-$10 more for these boxes for "preorder". There's a precident of WotC shipping exclusive items to stores, and allowing those stores to price them however they wish. For FTV sets, Masters sets, and special promotional products like the premade Modern Event Deck, WotC allows LGSs to price those products however they want. Until all of those products aren't exclusive to WPN stores, this will continue to happen because that's how a business works.

Granted, this is slightly different from my examples in that these are specifially supposed to be free, but if the store prices boxes at whatever price they want, then lower the price once the promos are given out, that skirts the rules.