Your seller sounds cooperative, and very well should let you review the financial data to make sure his expenses are accurate.

As a wholesaler it is important to be as accurate as possible when it comes to estimating repairs to gain trust, but with that said, you never know what extra things a rehabber might do to the house, so only estimate generally.

If I want to gamble, I'll go to Las Vegas.Mike

That's often more accurate than trying to get the info off a service.

IMHO, nobody can give you a spreadsheet that you can accurately use.

Is so, I can calculate the additional property taxes and subtract that by 10% of the rents, but I'm not sure if that's even accurate.

The estimates they cook up, however, are just not accurate at all.

Take this with a grain of salt though because I have never actually invested in either of these so my info may not be 100% accurate.

We've taken to tracking a 6 month rolling average on the advice of our statistical experts (to smooth out those bumps and to showing trending more accurately), it's easy to do in an excel ss when you're really trying to figure out what's cooking in a particular market.

I saw on Zillow my property is actually worth 258K, how accurate is that site?