There is no option to buy unlimited passes
No there is not
ok but can I use pay pal to buy passes?
You need cash on google play to buy passes.
Technically, if you keep buying passes, you will never be limited in the number of passes that you have. Your supply will remain unlimited to you; of course, there are different methods/options to buy passes. If you want to, then go ahead! Enjoy reading ; )
You can buy unlimited passes for a month for like $10, but you have to renew it every month.