Now, assuming this is a flip, if you find that agent and they tell you there are no accurate comps, that's a "walk-away" signal for me.

.#4 Transactional costs , depreciation recapture may add significant overhead#3 is always accurate.#4 costs are covered within, and with the kind of equity we're talking about here, should be minor. 

Gathering knowledge to try my hand at whole selling to get my foot in this business and start to build some capital.

It has limitations and some in accurate information.

How accurate has everyone found air dna to be. 

The BRRRR method is not for everyone — it’s best for those who have solid real estate knowledge and experience, and can accurately gauge market values, renovation costs and more.

Sometimes my projections are scary accurate, other times I wonder what the hell I was thinking.There is exactly a 0% chance that ALL of your pro forma projections will come true so accept that parts of your plan will go wrong even if you made the right decision based on the info you had at the time.Get a team, find colleagues and develop a feedback loop that’s able to give you the hard truth when it’s most needed.

Are their estimates pretty accurate?

Gather data that can help you make an educated decision. 

Once my lender was able to get back with all the accurate numbers for total monthly payment, and with how much the rents for similar properties were going for, I calculated a negative cashflow of -$600/mo to -$800/mo depending on if I rented the house for $2600/mo to $2800/mo.