That's just wasting time and energy right now. 

If there’s specific projects like electrical we get a project specific estimate after we put it under contract prior to the earnest money going hard.

I am considering purchasing empty lots priced roughly $10-15K below market value.My plan is to offer owner financing for the land.These lots have water, drainage, and electric connections available, and mobile homes are permitted.The area is experiencing significant development, with the lots surrounded by new single-family homes.I would really appreciate any advice, feedback, or suggestions.Thank you

This could affect markets relying on new chip plants, green energy projects, or other manufacturing, leading to increased vacancies and fewer workers.Conversely, markets with well-established job centers will be better insulated.

Already has some electric and plumbing hooked up.  

The main issue is that to do the ADU you have to spend so much bringing other items up to code like electrical, plumbing, lighting (windows) and egress.

Non UL electrical, plumbing &HVAC materials.

Insurers are looking at more than terrain, it's building, materials, electrical, plumbing, and roofs. 

Learning how to use the correct tools and materials for a job, YouTube videos and even ChatGPT will help you get through 80% of the problems you will run into.My rule was I would not mess with HVAC, plumbing and electrical Or if it would take more than a few hours. 

Rod is an ACTIVE mentor, which takes a lot of time/energy.