M.P.
I know you don't want to spend the money, but I loved Robeez boots for my daughters first winter. They were warm, cute, and stayed on. They are khaki so my son will wear them this winter now. I think Target has the knock-off versions. Ugg makes a boot for babies too that's adorable for like $50 I think. Robeez fit for a long time too. Unless your son's foot grows incredibly fast, one pair will probably last the winter. If you buy 12-18 month, it will be a little big now but you might get the whole winter out of them. My kids have small feet and wear their Robeez to death though. They are worth every penny.