What is a good website to order an unlocked iphone at a low price?

I want to get rid of my go phone but than I heard that you can put the sim card into an unlocked iphone. I want to do this, but I don’t know what website I should order an unlocked iphone. If you have swapped your sim into your iphone, what website did you use to buy the iphone?

How to find out Nokia handphone password in order to transfer account to another handphone?

How to transfer a hp account to another hp of Nokia with digits 013-xxxxxxxxx?

If I were to order a used Motorola Krave online, would I be albe to activate it with my Verizon account?

I would like to purchase a Motorola Krave. However, I am not eligible for an upgrade through my Verizon account so I would have to pay the full $350 for the phone through Verizon. If I were to purchase a used Krave online, through eBay for example, would I be able to activate it with my account? If so, how?