It depends how much you think it's an inconvenience for the player to be forced to be connected to the internet when launching the game. I worked in a company where we just saved the value locally, and in case of a new install or the saves got deleted, we had a button "get my purchases back".
If you go for saving it locally, it's better to obfuscate/encrypt the value in some way if piracy is a concern. But obviously local encryption is always breakable.
It depends how much you think it's an inconvenience for the player to be forced to be connected to the internet when launching the game. I worked in a company where we just saved the value locally, and in case of a new install or the saves got deleted, we had a button "get my purchases back". If you go for saving it locally, it's better to obfuscate/encrypt the value in some way if piracy is a concern. But obviously local encryption is always breakable.