Third party influence

I thought I had an ironclad deal that I have worked for the past two months.  Yea I have a lot of time involved in the thing.  Come to find out my buyer has been talking to homebuilders also.  Seems they are promising him the world.  Unless he is not telling me the whole story.  Seems they said they can build cheaper than he can buy an older one for.  Yea right they love you and will give you a great deal.  We still have a deal on the table right now I will let you guys know how it goes.  I don't think these people know which way is up right now.  This could get interesting.