My health care costs have a pretty clear soft upper bound given how HDHPs (and most plans) are structured. Deductible and out of pocket max makes it easy to be responsible and budget into an emergency fund.

In terms of non-exceptional costs, I'd say I spend about as much on medical bills every year as I do keeping my cars in good shape. Less than my house and less than I spend on hobby stuff, my cats' vet, or jewelry haha.