For T-Mobile CEO John Legere, poking fun at Verizon and AT&T is seemingly part of his job description. Whether he’s picking up their disgruntled customers on Twitter or coming up with Trumpian nicknames, respect for the competition certainly isn’t a maxim at T-Mobile HQ. The company’s latest stunt actually puts money behind Legere’s Twitter account, however, as T-Mobile is offering an extra discount to any AT&T grandfathered unlimited customers who want to jump ship.

As we noted last week, AT&T has hiked the cost of its grandfathered unlimited data plan for the third time in two years. The grandfathered plan is a longstanding thorn in AT&T’s side, and since it can’t formally kick customers off the network, it has been pricing them off the plan instead. Legere noticed the move a week later, and decided to offer any AT&T grandfathered unlimited customers an extra incentive to switch.

The deal isn’t bad: $250 via a prepaid card for anyone switching, and the deal stacks on top of T-Mobile’s existing Carrier Freedom, which will pay off your device payment or early termination fee on a different carrier if you switch. In total, you could be looking at $900 in savings between bill credits and pre-paid cards, although getting that much involves trading in an old phone and buying a new one.

The full details of Carrier Freedom (a longstanding T-Mobile deal) can be found here. The $250 Why The Hike deal starts Wednesday, June 20th, and run for a limited time. To qualify, you need to have a current and up-to-date Data Unlimited for iPhone on 4G LTE with VVM feature plan with AT&T.

Of course, as much as Legere likes to poke fun at the competition, T-Mobile is no stranger to quiet price hikes or shady activation fees, and its “unlimited” plan does have plenty of restrictions.

Chris Mills has loved tinkering with technology ever since he worked out how to defeat the parental controls on his parents' internet. He's blogged his way through Apple events and SpaceX launches ever since, and still keeps a bizarre fondness for the Palm Pre.