need to consider: tires, tubes, chains, cassettes, labor for repairs if you don't do the yourself; any other replacement parts. That would be a fair measure of the cost of the bike. Now a fair measure of the cost of participating the sport would include, shorts, jerseys, clothes, computers, water bottles, C02 cartridges, event entry fees, commuting costs to events, shoes, helmets, cleats, saddle bag, tools, the inevitable eventual pilgramge to the Tour de France.