When using the 1031 it will restrict the amount you have to spend on a new property.

There are lenders out there spending a ton on advertising with an army of correspondent's funneling them loans and many can very well be one and done borrowers because the loan servicing/construction admin is lousy. 

As a starting point: -If they work full time and make $700k a year -Don't want to or can't spend time self managing a short-term rental -Don't have a spouse who wants to take the lead on managing the rentals They are likely not going to directly reduce their taxable income with real estate year-to-year. 

Have yourself own an interest in the LLC, and have another entity you control own an interest and be the manager.  

I didn't spend $100 on both machines.

If you are worried about the price then the program isn't for you  but just consider you spend 4 years and about 50 to 100k+ to get a degree that pays you around 75k.

As I transition the property to a duplex + 2 ADUs, I am considering spending $10K+ to get another master meter put in.

If you’re in a market where you have to spend money on roofs, or exterior paint that’s ctainly you can save up for.

An appraiser likely isn't going to spend time giving you much feedback in advance (unless you have a connection or they are super slow).   

You can spend as little as $100 to form an LLC, or you could use an attorney and spend $1,000 or more.