However, do bear in mind that houses that are selling for 10-15K over asking price are being sold to RETAIL buyers from sellers who could afford to spend the time and money to get the house in tip-top shape to sell and who have the luxury of waiting for the sale to close.

Yet what is being sold to local and out of state folks are really pushing the numbers.

The BiggerPocket Capex article that I found shows $$ amounts for each big ticket item whereas the Rental Calculator is asking for a percentage. 

I helped a buyer purchase a three-family property on Bowdoin Street for $471,000 in 2003 which sold again for $515,000 in 2006 and helped another buyer purchase another three-family property on Nightingale Street for $125,500 in 2008 which sold again for $345,000 in 2009 so keep that in mind when rushing to purchase anything in this market...

Also, I would look at your original scope and compare with his change order invoice to see if any of the them items are the same or billed twice.

In my local MLS market, the RE taxes are itemized on the MLS report (which I can then verify through the municipality's web site).How does it work in VA?  

Over the past two years between rentals and flips I have bought and sold over 30 properties and I keep asking myself should I get my real estate license again solely for the purpose of handling my own transactions and having my own access to the MLS?

Guard against "burro-cratic" bungling as much as possible.There is story around about a house which sold shortly before the auction sale, but lender did not notify the sheriff to withdraw the property from the auction and it was sold again at the auction.

The cashflow was ok, but when I decided to sell the property, I sold it 50% higher  3 years later.

The unit itself was about 6 yrs old, but brand new and had never been sold due to the market crash so we bought it from the builder.