Owner builder with GC LLC business

[A G.]

I am doing my first build as owner builder and getting confused with that’s the best way to manage construction/sub-contractors like GC/builder. 

I have registered an LLC and incorporated business with contractor license. I am planning to use this business (SMLLC) to build the houses on my lots. I am wondering how I should handle the contracts/payments between SMLLC and ME (who own the lot) for the build. Should I be paying sales tax to sub contractors as owner builder, so use reseller certificate and then collect tax from ME. If latter, it would end up more expensive because if B&O taxes as well.

I am wondering if anyone else here has gone thru this journey and can help with some of these basic bootstrapping questions. 

Additional question would be, can the SMLLC build the house at a discount (taking losses for the business)?WA DOR says the sales tax should be collected on the contracted amount and doesn’t have any guidelines as to what that needs to be. I wonder if there is any reason why the business can’t do it at discount given it’s a new business and take losses to build the experience benefiting ME as the owner of the lot.