Actually it may be 81. Which is better than what I thought.
https://www.airportcitygame.com/threads/cost-for-land.17040/ - 2nd post
Many thanks for your reply and for the thread - the information contained within is good news, and very pleasing, that there is a long way to go before reaching that point in the game. Thanks once again.
Regards
Captain WH Rollins