I had one unlocked for a friend at the shop "exe231" mentions, one year ago, 1500PhP and after a few days the problem with cloud sinc and iTunes could not be fixed, he exchanged the "fix" simcard holder but let him pay for another one for 1200PhP, after a few days the WIFI did not work anymore, it was not a good idea, would have been better to sell it back home. He ended up buying an Cherry Mobile "Samsung" Clone for 10'000PhP and he is quite happy with it...
I still carry cheap phones cause i don't spend much time on the phone...I have been moving around so many countries anyway,so a lcked phone is not a safe bet....I looked up and you can buy them unlocked on Amazon...If you have to go through so much to unlock them later,it seems better to go through the little extra step of ordering them online and unlocked...Whenever I'm ready for one, I have to order an unlocked one and have a suite of sim cards.....I have a wifi only iPad for my smart device needs and 3 cheap $20-$40 phones to use for the occasional calls..Some weeks i only use the phone two or three times and if I'm in a new place,i may not use the phone for weeks at a time...so easy to lose and damage a cell phone,thats why i keep mine cheap and unlocked...
My son unlocks the iPhones here in Oz and does the same thing OzTony obviously does using the iTunes Account, works for him every time and has not had one lock him out yet doing it that way...