Okay let's make a computation, normally paypal buyers based the rate at
http://preev.com/btc/php and the current price is 211,000 PHP
while if you will sell your 1 BTC in coins.ph, you can only sell it at 205,989, so if we compare the rates, you can save Php 5,011 for that transaction.
Also, be aware that there is a fee when sending paypal from different countries, you can have it free if PHP to PHP but if PHP to US or other countries and vice versa, there's around $1-5 transaction fee, but that's negligible, you can still save a lot of money.
The main question now is finding a reliable exchange platform or person that you can sell your BTC for paypal funds. We all know the nature of paypal a reversible payment processor. so exchanging your BTC to PP is a high risk transaction not unless you find someone that is real legit paypal exchanger.