Option Agreement, Vacant Land, Pre-Paid Expenses

[Steve L.]

I have some funds in a couple different 1031 exchanges.  I have a piece of land under option, that I have been working with the City on a lot split and plans for construction of SFHs.  

Let's say my purchase price is 450k.  I have fronted 150k in expenses.  

The seller wants to carry financing now, so very little cash will be required.  

Can I have the Seller change the sales price to 600k?  Reimburse my contractors company 150k in costs through escrow, that way I can get more cash out of my exchange?

I have read about improvement exchanges and that won't work for what I am after.