I'm considering a commercial property with a short term remaining on their lease (3 years).

Problem is, I don't want to be tied down entirely from this pursuit.

PITI is $1430 and capex, vacancy, repairs, and PM make up the remaining $850 difference. 

I know that I can take the profit, pay no tax on 20%, but be on the hook for tax on the remaining 80%. 

Tying capex to the rate of inflation or tying capex to rent appreciation?

It's a higher rate and cost, but it doesn't tie you down.

Whether that's worth it or not remains to be seen.As @Jaron Walling said, if they've lived in it fro 2 out of the last  years they can get up to $500K tax free. 

You have gross rents, and can likely figure out remaining expenses (taxes/ insurance/ remaining utilities etc.) for an NOI.

Two major factors contributed to our decision; The way COVID was affecting the market in Austin at the time we were ready to sell, and a very generous offer from our contractor to foot the bill for the remaining property repairs, since we remodeled the whole darn thing, with the idea we would pay him back after closing and would sell through a realtor he recommended.

Some leaseholds are long-term and may be worth a look if they are likely to expire after you do (ie 80 years remaining on a 99 year lease).