City-Data, Neighborhood Scout and Rentometer are other sites I look at.

They claim to have good data, but some of what you are talking about might not be available more often than the 10 year census so make sure to check the data sources.

If not, anyone know a cleaner data source I could tap into for this kind of research?

I don't have enough data yet to quantify how much, but it does work.Hope this helped!

My opinion is that tax assessor data is completely useless for establishing property value.  

Their data is woefully out of date and useless. 0-2 is enough for me.

Hi BPers,I have recently tried to refinance one of my properties to get some cash out (property increased in value since I bought it a few years back).Problem is that since I already have 5 mortgages it seems that doing a cash-out is not easy and the best I could find is a 5/1 ARM with 8% interest.What are the possible ways to get cash out of a property in this situation?

The third column helps show forced appreciation or the ability to buy below market value.est cashflow (monthly)Cash on Cash return (annual)CoCr y1 incl appreciation or variance in value (minus 6% realtor fee)

@Kate Stallmann Not really enough data, but that's a very tight deal at best and it could turn quickly into a bad deal if there is any kind of deferred maintenance at all.  

I don't want to do the wrong thing here and purchase with the wrong data.