If your deal doesn't initially stack, don't give up...
Lee's golden nugget...
If your deal doesn't stack up and you are convinced that you can't reduce the build costs or increase the GDV... then look at the finance and investor numbers.
Every lender charges slightly different fees, for example, some charge 2% in and 2% out. Shop around and you may find a better deal than that.
Also, some investors charge interest on their loan/investment to you as well as asking for a split of the profits. Find one that is only asking for one or the other. Negotiate it as hard as you can to make the deal as better a proposition as possible to ALL stakeholders.
Remember - there's normally more than one way to make a deal work.