NEW. Own lot, have builder ID'd. Spec to build. How to structure?

[Mark Lupton]

Hello, I'm new to this site and see alot of good info! My wife and I came into a little money about 10 years ago. Bought a few lots in a lake area of Texas. We also had a second home there. Sold that and some lots. Have 3 left. Not been successful with realtors for last 5 yrs. Partially because I got caught up in the good economy and paid a little too much. Have come to an agreement with my original (2nd home) builder to build a spec home one of the three left. He's been a builder for years in the area. Built alot of spec homes in past. Has agreed in idea but have not contracted a deal yet. He is not interested in funding the build, as he's used to the investor doing the whole draw thing and won't likely be putting him on my existing LLC. I'm okay with it, but need solid ideas/options on how to do a profit split or cost + ?%. I worry about the true 'costs' as he's been doing this a long time and I'm a neophyte. I don't think he'll take advantage, but money is money and I need some ideas of the best way to structure. Appreciate any help! Mark