Can't speak for anyone else, but if I shot interiors and my style was straight lines, the movi looks like the deal, because a stedicam is never ever ever 100% parallel with anything.
I great operator can get close, but not 100% parallel.
Also 15k is a lot but to hire an operator, a focus puller and a f2. zoom is about 2 grand a day, so uh, where's my calculator . . well you get the idea.