Indiegala store, a quick question

try to add it again?

just thinking aloud

just buy 1 first and after that using your friend account to buy second gift :)) that for sure

You need to set it as a gift link. It will still add you a key that you can see, but as a gift option under the original one in your library.
Same goes for bundles, by the way, especially if you do the happy hour ones.

Some games let you change the amoun to buy in the check out.

Not answer.
But I will suggest you trade something for it here.
Brink of Consciousness is bundled several times.
Everybody who like hidden object games own many extra copies :P
Like me, I just traded one yesterday.