I have a blackberry phone and considering changing to iPhone 6 what is the ch...
Welcome to iMore! Check with your carrier first. Depending on who you're with they may be offering deals to upgrade. If you're in the market for a new carrier many are offering pretty nice incentives to switch.
My personal favorite option would be to go into an Apple Store. Since they work with all of the carriers they're pretty well versed in what all of them are offering as far as incentives.