Indeed, the formula is correct. Wikipedia maintains a list of historic Forever pricing: https://en.wikipedia.org/wiki/History_of_United_States_posta...

From the blog, the letter from California was dated April 2022, at which point the rates were domestic = $0.58 and global = $1.30. So the California sender correctly attached two domestics valued at $1.16 total plus an additional $0.14 to make $1.30.

> I think the UK sender didn't need to include _two_ global forevers.

It would be hard to know that ahead of time though. The global forever stamp is good for letters up to 1oz which can be as little as 4 US letter pages. It took the FSF 5 double-sided pages. Granted, it looks like lightweight paper & the post office doesn't seem to be very picky about this. But I think sending two forever stamps was being on the safe side.

Good point!

I think quoting that part alone, didn't make it clear I was referring to the whole article.

>...... "Oh Well."

May have been more apt.

Is eBay really anyones first thought when looking for a (non-collector) stamp to (actually) mail?

Perhaps he should have picked up a few £1 coins on eBay, use them to purchase some stamps from the post office?...

They needed US stamps.

I didn't see any request for a return envelope or stamp. Author decided to include them (unless I missed something).

It seems like common courtesy for me. Given the FSF are providing that service out of altruism, and are not the ones who neglected to give OP the license in the first place, it's only appropriate to not impose upon them to go buy stamps to send an international letter.

What about the paper, ink, labour involved? Why not slip $10 into envelope instead?

De minimis. You only include the extra envelope so that you can write your own address on it. Postage is the only real expense.

But, again, he was in the UK buying US stamps, so that the FSF could mail their answer back to him from the US. I don't think UK post offices supply all the world's stamps, buying that online from individuals who have them for sale makes some kind of sense, doesn't it?

I guess the a more "digital native" way would have been to first check if the USPS supports some kind of downloadable/printable stamping method, like QR codes or pre-bought labels (which, according to come early comment, they do).