I have been investing for 3 years and so far my cash flow percentage (out of total rental income) is around 1.5%.

You can't base all your work on AirDNA, but it's a great tool for making parallels and getting estimates with a percentage margin of error.

Whatever it appraised for, I would pay a percentage of the appraised value. - it had value adds. - it was in a high rent growth market.  

As others have mentioned, the percentage of savings you get back really depends on your individual tax situation, including your tax bracket, state, and other factors.

What percentage of commission and fees are typical?

I suspect that it is a VERY small percentage of leases.

@Ashley Campbell You are wise to engage an accountant who understands real estate and who has a significant percentage of RE investor clients.That said, it shouldn't cost anywhere near $5K for you to get answers to basic questions!

While a percentage set aside for repairs and maintenance doesn’t mean you’ll necessarily have enough stashed away for this expense it would certainly lessen the blow of the expenditure.

If the house is a 2nd home/vacation home, for example, and the owner lives in it for part of the year, they may be able to claim a percentage of the credit equal to the percentage of time they live in the property.

Buying a second property puts you in an even smaller percentage of the population than you already were in.