I've watched this happen quite a few times. Caught in the heat of the moment, someone would be told that the weight of buying every Japanese version of the first-generation Pokemon games was going to crush their debit card, and they would suffer what can only be called a sudden awareness of their mortality. At a horror convention, trying to balance a malicious spending habit with an income that fell between "No money" and "Canned ravioli is good if you steal your roommate's cheese to put on it," I tried to buy a replica Freddy Krueger glove.
As I totally overestimated how impressed the female population of my college would be to find a Nightmare On Elm Street prop mounted on my dresser, my debit card was declined so hard that the machine got a stress fracture. I slunk away and made sure to never walk in front of that particular vendor again, lest he remember my face, point to me, and exclaim, "Shame the broke dork!"
I was just glad that he didn't use it to cut my card.
But it's not just a lack of funds that will screw you over when you decide to purchase a mint Super Famicom that's still in the box. People weren't just yelling, "Excuse me, [bank of choice], but why do you hate me?" because they'd spent all their money on tickets and left none for trinkets. Their banks were just being suspicious that they were even at the event at all. You live in Florida, but you're suddenly four states away, trying to buy $300 worth of anime merchandise? Like the kids that returned from a Harry Potter movie with a sudden, unexplained interest in using the adjective "bloody" a lot, it's very fishy. There's no better way to say "I might be stealing this money" than by suddenly spending a month's worth of rent on a BioShock figurine in a different time zone.
You'll be the envy of everyone in line for the last bed
at the homeless shelter, though, so there's that.