How much does bicycle insurance cost?

It depends. If it is just a bicycle that isn't very expensive, or has a long warranty on it, then it doesn't really need insurance, mostly because there are little to no bike accidents where people are killed, and bicycles aren't all that expensive. If it is a very expensive bike (over $1,000 or more), then insurance wouldn't be a bad idea, but only if you ride the bike a lot, or if it is something very important to you. Otherwise, bicycles shouldn't have to have insurance - there's just no need for it.