Quote from @Andy Sabisch: Will it help you sell more or get more money? 

You will make more money on appreciation when you sell your property than you likely will from the monthly cash flow.  

This decision increased our budget from $15K to $45K, but it turned out to be a wise investment.The increased budget allowed us to enhance the property's overall value significantly, and we were able to sell it for a much higher price than initially anticipated.

This decision increased our budget from $15K to $45K, but it turned out to be a wise investment.The increased budget allowed us to enhance the property's overall value significantly, and we were able to sell it for a much higher price than initially anticipated.

How long did it take to flip your home  to be ready to sell?

This leads you to really having to target buyers who are looking for the home as a private home and not selling onto another rental investor.

If they can build a larger home and sell it for the same or more rather then building a couple small homes why do it?

A few that sell and manage, or know management companies.  

Their Goal - sell us this property seller finance. 

Are they really willing to sell and walk away with zero dollars up front?