You need to input your SASE details on the USPS website, they have a calculator. Once the results page comes up, scroll down as you are looking for the "First Class Mail International" price.

It'll be expensive as they count it as a package.

Save your stamps for a request in the future.

Ah ok. I will do that. How much should i put into an envelope?? Whats your recomendation? And what can i do with my stamps now. Haha. Thank you for your help, its appreciated

Exactly that.

On the rare occasions I use cash, I put the cash in a small envelope, mark it "money for postage" and put it in with everything else.

thanks, would i just put the paper currency in and they will use it the other end to pay for postage

No one here can tell you without weight etc.

Unfortunately it's going to be expensive, USPS count rigid card envelopes as packages which significantly increase the cost.

Try USPS.com there is a postal calculator on there.

Each Global Forever stamp is worth $1.15.

Honestly think for a package it'd be better for get hold of some US paper currency.

I have my global forever stamps but have no idea how many to put on the reply envelope? i live in the UK and will be sending my pictures and reply envelopes with royal mail but want advice on how many stamps to put on the reply envelope to make sure it gets back to me?? one, two, three i have no idea. (the reply envelope is A4 and rigid with cardboard) thanks for any help