Can anyone figure this out? zEstimate...?

I'm struggling with this one. Hope you can help! I'm looking at a REO and it's asking about 60k. However, I'm used to REOs being 10-20% discount from mkt (generally), and the zEst and Estimate Market Value by R/T shows $500k and up. When I look at the tract at zillow, all the homes are in that zest range, so the zest seems to make sense, BUT the Total essed Value (this year and in prior years) is always in the 40k to 60k range. Hmm, what's going on? I'm used to TAVs being relatively close (even within 10%) of current mkt values. THANKS if you can figure this one out. Kind regards.