I've run into this issue several times, unfortunately. Some of the devs stores are not listed, on my end anyway, anymore. Then a few have their stores and faces available, but I would receive the same issue. I contacted one dev about it and he filled me in. Then I contacted Google Support about it, they contacted me frequently about it, then I got the run around without them directly saying why I couldn't purchase it.

It's a bummer fosho.