Hi.
you will need to save it.
you can save an int using playerprefs but its better you purchase easy save (asset store) and save as a bool.
PlayerPrefs is very 'Hackable' and limited
When using playerprefs :
On the start of you game, check if the save reference (key) exists by using 'PlayerPrefs Has Key'
if it does not exists.
Create by using 'PlayerPrefs Set Int'. and set value to 0
Then go back to the state where you check if exists.
if it does exist.
Go next state.
in next state get the int value by using 'PlayerPrefs Get Int'
then do an int compare.
if int is equal to one disable the button.
on the buy state, where you deactivate when purchase is done ,
Use 'PlayerPrefs Set Int' and set it to 1.
The 'Key' should be the same on all actions as it is the reference to the variable.
i hope this helps.
