Property management is the loss leader, IE it's the steak on dollar steak night. 

Local Real Estate meetups with real estate investor association - you can try Googling REIA near your closest city or look on meetup.com along with here on BP.

I use Zillow and Redfin in addition to the Title Toolbox from Rebogateway to find the closest match, nearest physically, most recent property sales I can find.

See the closest hill to town, all rock and soil.  

Do they go into a restaurant and ask for a discount on their steak dinner? 

Your absolute best solution is to look at similar properties in same are and check some competition to get the closest approximation you can.

Rochester is the closest "big" town but that's too far away to have much local value I think. 

Each have their own draws, like Douglas lake is closest to Smokies so might not be the best pick if you're looking for rest & relaxation in your retirement but has good income, versus Watts Bar that's more seasonal renters but lots of quiet spots for retirement. 

I personally only have been using realtors to look for wore out properties (the closest thing I got vs the MLS).

After a guest mentioned that they had trouble finding us when they arrived after dark, I added a new house number at the end of the house closest to the driveway, which is lit by the street light.