You misunderstand: I would advise my customers of my price including delivery cost - best projection I can make, and let them know that is the case. Then stick with it. If they don’t like it, they can hunt around elsewhere, and in this environment, they’ll be behind the curve & likely pay more to someone else. They’ll learn. ;-)
I would never suggest going back on your (or my) word.
If your projection is too low, that’s on you, and yes, I’ve been in (basically) that position (I bid too low on labor to get projects, and ended up working for under minimum wage, but I did get a great reputation of going above and beyond and putting in whatever hours were needed to make it all work — on time.)
Yes, I did misunderstand you. I thought you meant that just because the freight had gone up since we had taken the order we should ask the customer to pay more than we took the order at. Which, IF we did that, the customer WOULD tell us to lose my number and rightly so.