The bag was incredible. Made of black vegan suede with two heavy silver chains for straps, the front was festooned with glittery resin gems of all shapes and colors. I had seen it months before on clearance at Barneys but didn’t decide to pull the trigger — I like to really obsess good and hard over my purchases — until it was too late and the bag was gone. So when it finally popped up again on the consignment site Tradesy, I knew I had to have it. The only problem? It was $595. This is an undeniably large sum of money to pay for a bag (though to be fair, it was more than 60% off the original price), but I knew this was the kind of extra-special piece I’d use for a long time. And there was only one available, so I had to act fast. There was some extra cash coming in from a freelance gig, but the check wasn’t in my hand yet, and I didn’t want to put it on my credit card. That’s when I noticed a small icon at the bottom of the page. It was for something called Affirm.