I am debating whether or not to buy an iPhone 4S or wait for iPhone 5. The only reason I haven't bought an iPhone already is because I definitely want an iPhone 5, but I'm not sure how my expenses would add up on a Sprint Plan ($80 / month, low-end Unlimited Plan) if I added my iPhone to my plan and somehow took my iPhone 4S out of the picture. would I have to pay extra per month to not use my iPhone 4S when the iPhone 5 is out, or is there some large payment I can make upfront to avoid a monthly payment until my iPhone 4S 2-year plan runs out? Also, which carrier has the best replacement plan? Thanks in advance.