Recently, I bought a phone for my family visiting, because roaming costs are so incredibly high for no good reason, and because it becomes hard to navigate the world without the internet (booking, GPS, etc.) I bought at $99, and paid a $50 data plan from Verizon (good deal given that the phone the MSRP is $249, that it’s a very decent phone, and that you can use it anywhere with any carrier — it has GSM, CDMA and everything you need.)
On the back of the box, it was mentioned that the phone could be unlocked after $50 had been made. I had just bought $50 of credit for 1 month of 4G with Verizon.When my parents left, I tried to unlock it. It was a bit confusing, but it did work!