I quoted a customer $130 for 3 day international shipping, which they paid. When I got to the post office, they wanted $230 for the shipping. I had made an error when I originally got the quote, and I'm wondering what standard practice is. (Side note: I figured out my error and it won't happen again.)
When I went through with the shipping, it was because I decided to eat the mistake.
I'm reluctant to ask the customer for the difference, as I believe this would be the wrong thing to do.
What do you all think?

