No problem, I don't mind helping out, and I really appreciate your thanks.

Lots of posters never come back let alone say thank you after I have tried to help

thanks so much, just what I needed to know!

Any stamps sold on the USPS website are still valid.

Older stamps are indeed also valid as long as the value covers the postage cost.

I just used the last of my $1.05 stamps (the ones they did a few years ago before introducing a Global Forever stamp), no problem with validity because I used enough to cover the current price.

If you are unsure then forever stamps are worth the current selling price, everything else will have a $/cents value on. The website has a price calculator so you can check current prices.

USPS don't accept web orders from outside the US on their website but will ship worldwide from their official eBay shop.

HELP!
I don't live in America and would like to include a SASE in a fan mail I hope to send there soon. There's a link to the USPS website, but ARE THOSE STAMPS STILL VALID? if not, where do I buy valid ones from? can stamps expire? if you use an older one, do you have to use more of them?
help much appreciated!