I've got one
While in Panama City, Panama we went to a bar to watch a football game. The taxi ride there was $3. So at midnight, when we were going back to the hostel, the taxi wanted $5. We said no, we'll pay $3. He left, next one, same thing... Third one, I told him where we wanted to go, and gave him $3 saying "OK?" And he said yes. So we piled in and off we went. Except he didn't know where our hostel was. He drove around and called a dispatch and no one knew where it was. So I told him to go down this road further and it had to be there. He went a bit, and then he said it wasn't down here, and he wouldn't go any further, it was dangerous. So we got out.
Standing in the side of the road, no idea where we were, lucky an other taxi pulls up. He knows where the place is, and tells us it is 7 blocks back the other way. We say we'll walk, he says no, get in, it's not safe and only $2... As we are getting in, a their runs up and rips my mom's purse off. I chase after the guy and he pulls out a gun. I duck and run back to the cab.
So in summary, we tried to save $2, and ended up spending it anyway, and my mother's passport was stolen (plus Kindle, lucky her purse was basically empty) we came out -$175 and a lot of hassle on that one.