I did about a 9 month stint at the Austin Papasitos back in the late 90's, and it always amazed me at how many repeat customers we'd get that were surprised by the menu prices. They's bitch on comment cards or leave shitty tips with a note on the receipt. And I bet half of what I served were enchiladas, which happened to be the cheapest thing on the menu. Why would you wait for 30-45 minutes to eat at Papasitos and then order fucking enchiladas? Always puzzled me.
Anyway, my favorite customer memory was this heffer that came in with her fatass husband and scarfed down 3 bags of chips with a large queso. Then they ordered chicken fajitas and specifically asked to not pour butter on it (yes, butter was poured before serving and a little cup was put on the skillet) because "she didn't need those extra calories". The chicken is served with the skin on, so I asked if she wanted me to have them cut the skin off the chicken as well. Nope, she was good with the skin. Great--less work for me and the kitchen. So I put the order in and call out no butter, and it comes out with the butter in the cup but not poured on the chicken. She throws a fucking fit. "I asked for no butter! It's not that hard to understand. Take this back and get it right." I explained to her that there is no butter on the chicken or any of her food, but it was left on the side in case her husband wanted it for something. "No, he doesn't need butter either. It's ridiculous that butter is even served with fajitas." OK, well how about I just take this to the back and get it off the table? "No, some might have spilled on our food. Take the whole thing away and bring us a completely fresh one." I just laughed and told them I'd bring them a fresh bag of chips so they wouldn't go hungry while waiting on a fresh food order. Husband's glare told me he was not amused by my comment, but he didn't have the heart to explain it to his wife.