From what I've read, this is really risky for you. Paypal can be charged back for like 180 days.
The longest time anybody can charge-back anything any ware is 60 days. Show me any ware in PayPal policy that they accept charge back within half a year.
It became officially effective as of 18th November 2014
"Users will be able to open a Dispute within 180 Days (with the exception of buyers in Latin America which must open a Dispute within 45 Days) of the date the Users sent the payment."