For me, it was a pair of merrell shoes on sale. They have lasted 3+ years, have great grip in the snow and ice, and so comfortable, my feet don’t hurt after wearing all day.
Never cheap out on anything that comes between you and the ground; shoes, tires, a bed.
What have been some of your good purchases under $100?
A bag of chickpea flour. Somebody on Lemmy was singing the praises of chickpea flour plus water as a replacement for egg in breading stuff. So instead of flour, egg, breadcrumbs I can do flour, chickpea flour + water, breadcrumbs. And then the rest of the chickpea flour goes back in the cabinet and I don’t have to try to use eggs before they go bad.