This allows the investors I work with to get a clear view of an achievable and accurate ARV range.

Are there any accurate property tax calculators for Northern Austin properties ?

I'm always coordinating with my contractor to get an accurate rehab cost.

When wholesalers provide costs to repair or revamp existing homes, how accurate are the calculations on their assumptions?

I don't know how accurate that metric is.

You could definitely start with buying a list but then that list can only be as accurate as the data provided.

That being said, according to your example one of the two is accurate?

Disclosures were not accurate which affect price/value of house.  

However the PM forgot to fill out a dollar amount that accures daily till case is settled so our default judgment is much lower than what actually owed. 

If you choose to hire someone to help you make phone calls, that is an added cost.With all of that said, however, knowing how to find leads, talk sellers into signing a purchasing agreement, performing accurate calculations to determine rehab costs and after repair value (ARV), finding a buyer and helping them close the deal with the seller is what to expect as a wholesaler.