depends on the kind, my kind of biking = $100 for the bike and maybe $20 for the helmet, and $50-100 in maintenance because sometimes I leave it outside in the rain. no lift tickets, insurance, gas or whatever to pay for. lowest end skimboard would be like $10 or $20 as far as I know...$120 for a good quality board, free transportation (bus or walk), a few dollars for waxeven cheaper than biking.some sports you can do on the cheap. others you can't (think skiing moderately expensive, and polo)