Someone go ask Srew Wilkins, what a fully set up, either track/tarmac or dirt Z will cost you, fully reliable, good HP, all the best gear fitted, ready for work.
It will be over $100 k
Look at Siddens's tarmac Z in latest issue of Tarmac mag, brilliant build, well sorted, that would be up thete $$ wise.
To set up a front runner Historic Group S Z race car, at minimum, $60 k, done from scatch.