At an investor conference on Tuesday, AT&T(s t) CEO Randall Stephenson expressed a pretty shocking belief: Carrier subsidies for new cell phones must come to an end.  According to CNet, Stephenson thinks that wireless carriers need to shift their focus from getting new customers on their network to getting current customers to use more of the network.

For consumers, this would mean the end of paying $200 or so for a new phone on-contract every couple of years. Instead, buyers will have to pay full retail price for phones, which is usually much closer to $500 or $600.

This isn’t just a grab for more money. According to Stephenson, “When you’re growing the business initially, you have to do aggressive device subsidies to get people on the network… But as you approach 90 percent penetration, you move into maintenance mode. That means more device upgrades. And the model has…