Since your an estimator are the materials and labor based on facts (i.e. hard costs a labor units) or a guess.Nothing personal but I wouldn't consider anything you wrote there, if I was buying I'd do my own estimate/SOW. 

Or should I just exhaust the heloc and keep buying houses? 

Purchase price: $45,000 Cash invested: $45,000 Single family buy & holdHey @Malcolm Grundy!

And that’s if you can’t find something to buy for under $100k or time multiple sales at once. 

The tax advantages of buying/holding gas stations are pretty great.Many of the components of gas stations including pumps, tanks, external parking areas, and other equipment are classified as either 5 or 15 year property so you can bonus depreciate a lot of it (minus the land value) and get significant deductions in year 1.With the 2025 bonus depreciation rate at 40%, a $1 million gas station acquisition could still lead to $100K+ in year 1 deductions depending on the specifics of your deal.

Reason is a Heloc generally carries a higher rate on a shorter term and "Can Never" be used as an "Asset, or for PITI reserves" which are both required when you buy an investment property. 

One I close on that house, I plan to go buy a good lot and get a decent builder to build the next one. 

Some ideas I've considered:Equity Buyout: Having another investor or my partner buy out my 40% equity.Seller Financing: Selling my equity and offering seller financing to the buyer.Selling the Property: Liquidating the property entirely and splitting the proceeds.Does anyone have experience with situations like this?

He claimed if he didn't get the money he could not buy supplies to complete the job, which would be done in a week(I knew this wasn't true). 

Management would be self-managed, as in this example it would be a client's first rental buy and hold.