Not a horror story, but I'm involved in one of sorts right now. I sold a chunk of cards to a guy, and he was paying me when he could, and I was shipping that value of the cards he bought. Well after the first payment he ran into some personal problems in life, and our deal has been on hold for a few months now. So while I hold no ill will towards him, it does suck that life can interrupt a payment plan if it isn't a one time deal.