"The cashier made a big deal about it when I went through the checkout line, laughing loudly at my stupidity for purchasing such an expensive model and actually

"The cashier made a big deal about it when I went through the checkout line, laughing loudly at my stupidity for purchasing such an expensive model and actually exhorting the cashier in the next lane to do the same.[..]I was really embarrassed;" I'm sorry you experienced something like that. That is a positively horrible thing to do to a customer. I would have gone straight through to the manager to complain. And then I would have told him I'm not buying it, and he can thank the two cashiers for that. That would have probably been quite a chunk of their salary that they wasted for the store. They would have probably gotten fired for it. It's one thing to give advice, and a nudge if a customer is misinformed by the sale staff. It's something completely different to mock/embarrass him for whatever smart/stupid buying decision he makes. On the plus side, at least you're glad about your purchase now and have gotten a good deal for your money 12 years later.