I also bought some 2 ounce stamps, overstock, at a discount. The current value is 84¢, they are also forever stamps. That plus the 39¢ surcharge is $1.23, I'm making notes. If I have a 2oz flat, I can put one of those and 39¢ in any postage, and making sure I have the non-machinable labels stuck on it, which I just printed a bunch, in theory I should be fine that way as well.

Next order from Vistaprint I'm getting a red rubber stamp and that will make things easier than printing and cutting labels.

39 cents was an old postal rate years ago. Time to hunt for some of those on sale. I used all of mine over the years, mailing postcards.