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.

Luckily I have not spend any money on any "guru" courses.

How much did you spend in the rehab?

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

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).   

Your best bet is to set goals related to deal-finding and spend your time on that right now. 

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

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 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. 

This all comes down to how much you are looking to spend and the class of property/class of tenants you want to deal with.