You know, AF1 isn't like any other aircraft in the world. Not only does it have lots of really cool communications gear, it is also modified to be able to be strong enough to maneuver if needed (banks and turns are hard on an airframe). And, there is also the little matter of the various defensive gear it has, like chaff flares and other stuff.
If Trump thinks he can simply keep his airplane and use it while he's president, charging the taxpayer for it's use (which he does), he's got another thing coming, because his plane isn't even 1/10th as capable as what AF1 is.