Ours was a mandatory half up front. And I don't have $60k laying around to buy my way out of active duty.
Plus, in all honesty, I like my job, I like my jet, I like my coworkers. Sure, Big Blue took a dump on my career. But that doesn't mean I want to leave my current situation. I especially don't want to go ART and lose one weekend a month while still working during the week.