Buying a new mobile phone is a nightmare! You find a phone you like, but it only comes on a hideously expensive phone plan. Or you find a suitable plan with the provider who has decent coverage in your area, but all the phones are useless for your needs.
The market needs simplification - maybe a mix-and-match system. You choose the plan you want at $x, and the phone you want, at $y, giving a total price per month = $z. And an easier way to research all the different plans out there. I'm certain that part of the reason carriers have so many different plans and prices is so that once they've got you, it's too confusing to be able to find out if you can get a better deal elsewhere, so they keep you as a customer.