Ripped off...maybe

When I walk into an auto shop with a problem and they tell me that it will cost x amount I think to myself am I getting ripped off. Man, if only I would have taken auto shop in high school. I think when we are done here I will take an auto shop class at a community college or something. I don't like walking into a situation where I know nothing and the person behind the counter knows I know nothing. I would love to go to a shop and say my car is doing this and I think it is this and I looked it up and it should cost around this to fix. Then I think we would go somewhere and I wouldn't feel ripped off...but as for now only the person behind the counter knows if they are ripping me off.