I'm making a web-application that requires 1 single $10 payment on the 2nd of each month.

How I want it to work is this:
1- User signs up & get's 1 month's cycle free
2- Then, access is disabled until they purchase access again (hence, the monthly)
3- Once Payment has been made (via PayPal), a script is run, telling DB that payment has been made
4- Access is granted again.