In my case it depends on the person asking. To one person, a friend, I jokingly said I could have bought a motorcycle for what it cost and to another person, a long time member of our bike club, I told him what I paid. I guess a lot of people think it's rude to ask but I don't look at it that way. Would I think it rude if someone asked how much I paid for the sandwich I was eating? I think people only think it's rude when the price is high. But I could be wrong. I've asked but I always preface it with - you can tell me to mind my own business, but ... Some people just don't like to talk about money. If I really think they are into bikes and would really like to know what kind of money it costs to own x type bike then I would tell them. But I like Lisa's answer for casual inquiries.