Hi savoir,
If you encounter pay error while you purchase a pakage, pls follow the instructions to reset your google play configuration:
pay error 3:check the payment configuration as what indicates in this link:https://support.google.com/googleplay/answer/9037938?hl=en if the problem still exists, that might because of google does not work in your area.
pay error 6:the account is not safe, pls change to another google play account
Pay error 7:Clear data of google play:https://support.google.com/googleplay/answer/7513003?hl=en&visit_id=637284104073170608-2210111938&rd=1
Pay error 9:check the payment configuration https://support.google.com/googleplay/answer/9037938?hl=enheck your google play setting according to the list below: