Don't trust Zillow yet
Zillow is not right yet! I'm in real estate- you can get the same info from the county recorder's office- most are on the web now. Do a simple search on Realtor.com. If you really want comps, just call your local hungry realtor, they do it for free and explain how they got it all. Just be nice to them, they don't get paid unless they actually sell something, so if they do a good job and can demonstrate how effective they can sell you house, give them the listing.