I have a store with a few variably weighted products. I have the weights of these items so correct, that I can pack an order of 6 or 7 into a box and it comes up with an estimated weight exactly, give or take an ounce. And for example it the postage calculator will tell me it cost 8.50 to ship it out, yet my customers are paying $15, $16.
At one time I had $.25 per item set up for a handling fee, but I got rid of that. And yet that didn't solve it. I see this has been an issue in other threads, but I don't see any resolution or why this is happening.