A tried and true measure that has been around for a long time and is still relied upon today is the ratio between median household income and median home prices in any given market.  

I estimate 2%, but that's usually on the high end.Seller concessions - varies by area.  

If you aren't relying on a lawyer to review everything, it's very important to stay educated and not get too creative.

I doubt you'll get many replies, but I'll pose this one question: if you are investing in real estate to secure your own financial future and not rely on others for support, why would you leave your security in anybody else's hands than your own.

@Chris Berg the loan position information in PropertyRadar is based on computer models, and while it is a great starting point it should not be relied on for purchasing at auction, as per the disclaimer in the software.

We were given a 30 year limit but we want to get it all paid off for when we graduate so we immediately have positive cash flow to rely on.

Like most towns it varies from really nice areas to "war zones".  

In my state, property taxes can be low due to Homestead tax exemptions on primary residence, especially if the owner has lived there a considerable time, because there's a cap on tax increases each year for homesteads.It's always a good idea for agents to forewarn buyers not to rely on property tax estimates long before closing.

I relied on a professional who didn't do their job, but I am willing to take the responsibility which is why I said "kind of ..."  

On average I try to spend 10k or under on new purchases to get them ready to be rented and under 5k every time a tenant decides to destroy a property but it can vary a lot depending on how much of the work I decide to do myself and the pricing of the people I decide to hire along with what all needs to be done.