Supporter PAck

I bought the basic supporter pack to see if I like the game. Turns out, I do. I would like to get an additional supporter pack for the vanity items as well as to support ongoing development. If I were to buy another supporter pack, would I also receive another beta key? I would like to be able to give it to a friend, if that is the case. Thanks

If there is "Beta key" in the description of the pack you want to upgrade to, then yes you get a beta key.

After buying you should find it/them here:
https://www.pathofexile.com/my-account/transactions