Don't forget, the type has no civil CofA, so you'd have to go through a lot of work to get it into a PtF, then still be restricted to day VMC, and need permission to fly it outside of the UK.
I believe it's possible to get a Pilatus PC7 Mk.1 with an EASA CofA, that would not have those restrictions, and probably be a better aircraft anyway. (Having done quite a lot of flight testing on the Tucano early in it's RAF career, I'd agree with most of !!!!'s criticisms, and could add a few dozen of my own).
But, I still hope that I can buy one, it'll make a great engineering teaching airframe!
G