No doubt that the sums will add up and that you may even have some dosh left at the end of the 10 years; unless something went pretty badly wrong.
Am sure not every TB9 owner started off with £150k before they committed to buying one!
WHY would you want to buy a TB9 though?
There are a gazillion other aeroplane/engine combination that are so much nicer to fly for the same or less money.