Then I save that amount each month in reserves until I need them.

If your exchange is not done properly or your funds are not safe you are going to kick yourself for trying to save $500. 

You can save and have a foundation to do your first fix and flip

My suggestions would be in this order:(a) Determine the type of financing you qualify for - this will short cut the process considerably and save time on investment angles and next steps.

So if the homeowner saves energy or goes on a long vacation, they still get charged 100%.

After discussing their goals, we realized they would like to maximize the property's value while also including me in the process, given my background in general contracting.

Eliminate debt, establish a budget, and save.

Eliminate debt, establish a budget, and save.

It’s also important to be as specific as possible in the scope of work for each line item—clear details can save you from misunderstandings or unexpected costs later on.I specialize in consulting services for situations just like this, helping clients work confidently with contractors by bridging the knowledge gap.

I saved up the down payment for a few months and have a few remaining as emergency funds.