Sales can go away if the sale expires before you buy it. That's like saying, "You had this product on sale last week, but I forgot to buy it when it was on sale. Can I have it for the sale price?" NewEgg has no obligation to give you a sale price because you didn't buy it before the sale ended. I don't see any wrongdoing here, minus a user who doesn't understand how retail works. Sounds like a learning experience to me. Ignorance is not bliss in this case.