Once you get a feel for one property, you can gauge most in the same area. 

I bought a property that needed a gas line pressure test.

I’ve only monitored a few online auctions just to gauge how people bid and assessing how much they pay for specific lands (which seem much higher then what I thought they’d pay)Thanks for any help,Some Newbie from Florida

If a group of homeowners truly wishes to prevent their neighbor from performing activity "XYZ" in their proximity, there are social constructs in place for that (HOA, peer pressure, "gentlemen's agreement"); these entities/ideas work well because they are limited in scope and require buy-in. 

I used rentometer to gauge my price range, as there are not a ton of homes that are this sqft and as nice of quality to compare to right now.

My argument is that he told us other buyers wanted this property and put pressure on us to put the money down without seeing it.

I don't think she's trying to screw me though, there's no pressure.

That might relieve some of the pressure you're feeling about having to make a decision based on the tax issue.

You can talk to local and regional production builders to gauge their appetite and opinions about the market and potential of the area. 

That being said you can hedge new inventory pressure by researching the markets you want to invest in and find out how many units are in the pipeline.