they've taken over my mind

I was at Momoko today. They've got a sign that says "If you break anything, you will have to pay full retail price for it." Immediately I thought, "wait, wouldn't that put the seller in a better post-contract position?" Because if you break it, and pay full retail price, then the seller gets damages (price he paid for the item) plus net profits (markup), so he gets a profit even though he hasn't really sold anything--so if he buys a replacement and sells it, he has two profits for selling one item. Then of course I realized that was stupid, since it isn't like he could sell the broken one, so seller should get the benefit of his bargain and expectancy damages and all that. Then I wondered if that was even an enforceable contract, or if it was more of a quasi-contract, because you can't recover on expectancy in a quasi-contract. And then I realized I need to get out more.