AT&T has announced incentives worth up to $450 for T-Mobile customers who switch to their service. The move is being made in response to T-Mobile’s Uncarrier offers, after AT&T recently said that it too expected to move toward separating device and service charges.

Proving the old adage that there’s no such thing as a free lunch, the deal of course comes with strings. First, $250 of that is the maximum you’ll receive in return for trading in your existing T-Mobile handset. To get the full $250, you’ll need a recent handset in good condition – in which case you’d almost certainly get more selling it privately …  expand full story