What is something really stupid you purchased that turned out far better than expected?
I bought a piece of 1.5 inch stiff foam to try to fix a sag in a bed. It didn't work but having that thick piece of solid foam around has been a life saver.
Need something flat to put a laptop on? Throw it on the foam. Going to be doing something that requires you to be on your knees for a while? Get the foam!
It went from stupid purchase to something I'd gladly replace if it broke.
I'm far from a coffee snob, but figured I'd give this $25 piece of plastic a try because a good friend was raving about it. In the year since, it's been my favorite way to make myself a cup of coffee-- the ritual of it helps me structure my Saturday morning, the coffee tastes better than I thought coffee could taste, and I'm more excited to look at the flavors and whatnot from locally ground coffee.
Cheapest and easiest way to get into espresso-adjacent drinks. Is it going to give you that espresso experience? No, but for literally 1% of the cost of an actually decent espresso machine, you can up your coffe game extraordinarily.
Get an Aeropress, a good grinder with fresh beans, and a digital temperature kettle, and you'll be shocked at how good coffee can taste.
My parents got me one to use on motorcycle camping trips a few years ago, and it's so handy. I'm thinking about one of the larger ones to keep at home.