Rant: USPO No help at all

I need to post a birthday card to my Mom in the UK. How much does it cost in postage I wonder? Try asking the USPO. In order to get a price calculation you need a scale that will weigh your mail. Sorry USPO but I don't keep a freakin' postage scale at home. Now that may amaze you but it's the honest-to-god truth. I bet lots of other people don't have a postage scale at home either. While I know that this must astound you (how reckless that the mailing public could possibly be sending missives without accurately determing the weight of said communication) perhaps you could help me (and probably lots of other folks) by, oh I don't know, listing the costs for mailing popular items. Like birthday cards. I bet you carry a few of those each day.