Regular paypal. (Paypal = paypal)
SAI license is based on
system ID of the PC/laptop it is installed on, that is the ID you need to fill in order to download the lincense. Each of your
PC/laptops will have a diffrent ID and will need a separate license = you will have to
download a diffrent lncense for every sinle PC/laptop you desire to use SAI on. Hereby, you make are making
only 1 lincense purchase ( assuming
you are the only person that would be using the software) this single purchase is eligible to download
several license certificates/files, or whatever it is called.
Hope this made it clear... even though i doubt it did...

You'll get it once you figure out how it works
It is only 50$ or something... jeesh ppl... you spent more on junkfood, videogames and shit...