If they advertise something, they have to honor that price - It's illegal to do anything else, no matter who's at fault or how large the discrpency is. I have this problem all the time with my local Walgreen stores - they put the sale prices up 2 days before they go into effect, but won't honor it (even tho it's the display/shelf price) - I've reported them many times and been told that if a company/business advertises a price, whether it be in an ad, a shelf, or on the product itself - they are legally obligated to sell the item at that price. Of course they can fix the problem, but if someone attempts to purchase an item while the incorrect price is displayed, they are supposed to honor the display price!!!
If they incorrectly listed a Balenciaga for $130, and someone tried to purchase it, then they are obligated to sell it at that price - - they are essentially breaking the law (common law called "Bait & Switch" or "Scan Scam")!!