But if we sold the land to the builder with comps close to 240k in that area, you would still make > 20 grands.

Before I closed on the property, I'd expressed concern to the builder about the side yard which had, what I felt, was a significant angle.

I am a builder/developer and would be happy to answer any questions that you might have. 

I have an incentive of $25,000 for going with the builder-specific lender, and I'm trying to figure out the best way to utilize it.

I only ask because I work with a few different builders that have 2-4 units in growing markets.

I trained and set up the same type of seller financed side for the largest home builder in the state.

In my opinion, it can be a sign of builder/investor confidence in a given area if they're willing to put up the capital to build new homes in a given area: they believe there will be enough demand to sell their new products.

can someone tell me which builder would allow investors to buy their house.

A builder’s risk policy is also worth exploring, as it can protect the property, materials, and equipment during your restoration work. 

Apply to work for a builder/contractor.