Maybe they get mad and hang up.

Right now there is a lot of work out there and contractors will seek out the low hanging fruit first...that is, projects that pay well and clients that are easy to work with. 

@David Kuhlke hang in there.  

What could be the cost associated to hang it with any broker?

Please never put all your eggs in one basket again, an Agent may have suggestions of people they work for but they are not supposed to say use this guy especially if they have a financial connection. 

They are hanging around for a reason !

If real estate is really something you want to do, just hang in there.

They own say 10 retail centers but do not want to have full recourse of tens of millions in debt hanging over their head.

If you don't do that, with strict boxes around different scenarios, you're 100% going to get mixed up and mush Freddie and FHA and Fannie guidelines together into a confused basket of confetti that makes no sense.

It could be added into the option consideration or they hang onto to it until the purchase.Depending on the state where the property is located, you can looking into land contract sales.