Of course OP had all the rights to buy it for that price. And she just wanted to share her find, nothing else and got herself in trouble not in a store, but here, on Dis, ironically enough on budget board. And stores do actually mark sometimes extremely cheap if product is about to expire. I once found yogurt, 4-pack for 25c, those usually $4. They were expiring in few days yet still perfectly good for those few days. Lets say we got a lot of calcium. 
