Appraisal Value VS. Estimated Value

[Jason Rostar]

Hey everyone!

If someone has already answered this question somewhere and could point me in the right direction, that'd be great! Otherwise.... My situation is as follows: 

I used the VA loan to get a property. The seller put the home up for 350k - I offered 350k - then an appraiser said it was only worth 280k and the VA would only fund it for 280k. I offered 285k and the seller accepted, luckily, as I had about 2k of skin in the game at this point.

Fast forward 4 years later and I'm ready to sell this property. Zillow says it should be worth 470k (I understand that Zestimates are accurate within 10%-20%). How do I make sure that I don't get into the same situation that the previous seller was in? It is currently rented out. Should I try to make a time for an appraiser to look at the property before putting it up for sale?  

Thanks in advance!