No one is perfect but you don't need to lie....

I rarely sell parts, but occasionally....I have noticed that USPS has the same rate, within a few nickels, priority vs "just in a box, weigh and measure it deal!"!!!!
I do a lot of flat rate pads and boxes. Also if it's some what local(east coast) I use the regional rate boxes. They dont really work good if I'm shipping to like the west coast they get expensive. Anything other than that I send ups ground. I despise FedEx