I once had a guru say that people who use their own money in real estate are lazy.

You can always sell without an agent, but it could cost you more money and more importantly, money in the long run..think of it like this…maybe a strong buyers broker would’ve urged more caution with the initial purchase? 

If you would have simply held on and collected rent for 72 months, you would have been up money...and that is buying at the peak right before the biggest real estate bubble in modern history.

But a good skilled worker, whether GC or sub's, can be invaluable.With all that said, to try and save money, I would see if you can find a good home inspector referral, many of them are or were GC's themselves, and pay them to check out important work that you have done.

Is the reason why this is lucrative to the seller because it's money that is able to be written off as a loss? 

Are you spending money on lead generation?

In growing markets I’d always recommend BRRRRs over flips if possible.You'll probably still have to keep money in the deal but it's way better than putting down the whole 20% LTV. 

Which would have kept more money in my pocket.

I would be using all of my own money for both the acquisition and the rehab.Also, I would (attempt) to GC this myself to save on the rehab.

If the tenant fails to complete the job, or does it poorly, you'll have to hire someone to finish/fix it and you'll be out the rent money.