Giving up his place on the property investment waiting list in return for a sum of money

Praise be to Allah.

There is nothing wrong with him giving up his place on the property investment waiting list in return for a sum of money, because he is giving up a financial right, and it is permissible to sell financial rights in return for compensation. But it is essential to have the permission of the bank handling this investment. If the bank gives permission and the two parties agree that one will pay money in order to take the place of the other, then this is permissible and there is nothing wrong with it. 

And Allaah knows best.