I looked into the US Postal Service increases today. I had promised that I wouldn't raise rates when they did, rather I would wait until at least June 1. I waited until June 11. Ouch - that hurt. It is hard to analyze the increases, but I took a sampling of old shipments in April and compared them to the new prices. They ranged from a 10 - 20% increase. I split the difference and raised shipping rates about 15%. I really hated to do that - I had always tried to keep them low. My aim is simply to break even on shipping.