Describe an item on which you spent more than you had expected

I want to talk about a pair of running shoes I bought last year, which ended up costing almost three times what I had budgeted. I'd gone into the shop intending to spend about a million dong on something basic, because I'd only just started running and I wasn't sure I'd keep it up. The assistant asked to watch me walk, pointed out that my feet roll inwards, and suggested a pair built for that. They were far beyond what I'd planned to spend, and I stood there for a good ten minutes talking myself out of it. In the end I bought them, mostly because I'd had a recurring pain in one knee and he seemed to know exactly what caused it. I felt slightly sick about the price on the way home. But a year later I'd call it the best thing I've bought — the knee pain disappeared within a fortnight and hasn't come back, and I've run in them almost every week since. It taught me something about false economy: the cheap pair I'd have bought would have been replaced twice by now, and I'd probably have given up running altogether.