Its no problem to live in Philippine on 1500 dollars a month. Travelling is not expensive. The lowbudget airlines Cebu -pacific has most of the times promos, the you can buy tickets for a domestic flight for 50 dollar , for a distance of 1000 kilometer to the south of north of the country.
Travelling on the islands is cheap also as long as you dont rent a private car with driver. Travellin with a local bus, non aircon, but open windows, cost only 2 dollar for 100 kilometer distance.
In the provinces everything is less expensive than in big city. Even cigarettes and local rhum are not expensive. Try the famous Tanduay Rhum distellated from sugarcane, less than 50 peso foor a bottle