How accurate are Eppraisal and Zillow?

I was really surprised to find out our house value may be even lower than I had thought. So I wondered if my neighbors were in a similar situation. Turns out Eppraisal and Zillow vary quite a bit, but it's not always Eppraisal that comes in lower like it did in our case. Here are some samples:

Next door neighbor 1:

Next door neighbor 2:

Directly across the street:

Next door to across the street 1:

Next door to across the street 2:

Behind our house:

So only one of these looks similar to our house. The rest actually have optimistic numbers for Eppraisal compared to Zillow.

So I don't know who to believe. The best thing to do would be to have an appraisal done, but last time we did that it was $500. We had the appraisal done in order to refinance in Fall of last year. We were not qualified because we owed over 105% of the house's value at that time. I think the value was appraised at $200,000 at the time and we owed about $210,000. Now we have the mortgage paid down to a little over $183,000, and the interest rates are even better than the were last year, however it appears our house value has slipped even lower and we still owe more on our house than it is worth. I'd love to try to refinance at the great rates available these days, but don't want spend $500 for another appraisal only to be rejected again.

Anyway, here is one more example of how these could be completely inaccurate.  My parents live in a different part of town, so I put their address in and difference between Eppraisal and Zillow was huge!  $85,485 difference!  And Eppraisal had the higher value!

So, I don't think I will be including the house value in my net worth updates in the future because I don't have an accurate number. Even the mutual fund prices change so much, I might only do updates once every quarter for now on.