I'm not sure how to ease the burden of a new rule going into effect for the USPS. It's not just the creeping up of postage rates. Effective this Monday, merchandise is no longer permitted to be shipped in First Class International Flats, which is what I've been using. It has to go as a First Class Package. This affects orders to shops as well.
Here are some samples of the crazy rates. One standard full size chart in a rigid mailer, typically 6 ounces.
To the UK:
Let's say you want a couple charts and it now weighs 9 ounces.
The shipping label service I use, stamps.com, has some whamodyne new program that is supposed to ease this burden of more than doubling of the shipping costs. As it is, I've still had to raise my shipping rates substantially. You can read about it here. The hitch is that their system isn't working yet. If you can get it to run (first major problem) and get it to print properly (second major reported problem) and you get charged properly (sadly also a reported problem), it sounds like all mail will get sent to a clearing house in New Jersey, where it may or may not be sent on. There are no barcodes on the new labels (which I can't print yet, btw) so very little is understood about the tracking and subsequent journey.
I will leave you with the note that this is day 1 of the new system. Things will surely get better, or a new system will come along. Surely this affects a huge number of small business people who are not going to stand for it. I will keep you updated.