Welcome Richard!
As diamondedge and and mason already pointed out, confirm what type of new engine was installed (stock? modded?), who did the install, and if the dealership is willing to extend warranty on it. As far as price goes, I would say from a dealership this is in the right ballpark for a sport-tech, considering a new engine has been installed and everything else is in excellent condition.
Enough research on here and you will discover a wealth of knowledge on how to *hopefully* maintain and extend the life of the engine - oil changes more regular than dealer spec, checking oil at fill-ups, performance mods mean tune, general maintenance, etc. I'm sure with your experience this doesn't come as a surprise though.
Good luck in your hunt for an 11-14 hatch, they are definitely on the harder side to find.