I ship them flat rate just to get the security of the confirmation #. Here towards the end, it is cheaper because you can ship up to a certain amount w/o it costing anymore. I love the bubble envelopes. I put in a finished lap quilt into one of thos bags by putting it in a plastic bag, sucked all the air out with the vaccuum, then tied it shut, and stuffed into the flat rate plastic bags. Works like a charm. You may want to try that and only pay for the envelope.