How about a things customers tell dealers.
Me: Hello, (insert motorcycle shop name here)
Her: How much to fix a tire?
Me: What kind of bike is it on?
Her: A dirt bike, and I don't want to spend a lot of money.
Me: If you bring the rim and tire off the bike, it's $20 in labor. Depending on the problem with the tire, you might need a patch or a new tube, or a new tire, so that will be extra.
Her: So it's $20 out the door for all the tires then?
Me: No, it's $20 per tire for the labor. What you will need to fix the tire will be additional.
Her: So for 2 tires it would be $40 total then?
Me: For the labor, yes. But you will likely need new tubs, and maybe some rim tape, so that will be additional.
Her: But you said it was $40 total. I am on a tight budget so I need to know exactly.
Me: No I did not. I said it was $40 for the labor. If you know the size of the tires, I could look up tube prices and get you a better quote. But you still might need rim tape, have loose or broken spokes and other things that add cost.
Her: So it's $40 for both tires then?
Me: For the labor, yes. (I gave up at this point)
Someone, not her, drops off two tires the the guy at the counter explains that two tubes will be needed and they are an extra $10. Bringing up the total to $60. He said that will be just fine. The tires are fixed.
Before they are picked up, the word of the extra $20 for tubes gets back to the lady and she calls me up. She was irate that I didn't quote her the right price and she has to pay $20 more then the $40 I told her to it would cost. She beat up on me for a good 5 minutes, but said she would pay my overcharges.
The part that made it all better was when the guy came to pick up the tires, we asked him if at anytime we where not clear on the price and told him about the phone call. His responsive, "Everything is fine, she is just a b*tch.".