If you mean pricing from amazon and third parties, it's safest to buy from Amazon themselves (not always the lowest price), then those fulfilled by Amazon (the goods are sort of consigned to Amazon), then other third parties (be sure to buy from some with plenty of high rating). Not all third parties will ship to the Philippines.
If you mean shipping, then go for the lowest one. The higher priced shipping are often through Fedex or DHL, where oftentimes, you get taxed. If you have a JohnnyAir account, then ship there. If you buy plenty of items from Amazon, consider getting their Amazon Prime program...