How to buy for the right price in your market?

[Pedro Hernandez]

Hi All, 

I have another newbie, very generic question. 

I was looking at a property SFH 1/3/2 Listed for $449,000, county appraiser values it at $320,000. I have done some comps on zillow(not sure if this is the best site to use) and most houses in the last 12 months has sold between 350-450. Rents in the area are about $3000-$4000 range.

How do I determine what these units are actually renting for?

How do I determine what a good offer could be?