Not all home owners will put value in owning a unit in the back of their house or worse, sacrifice their garage for one.Here is a specialist that I reach out to sometimes with questions: ADU Pros (google them because I can't put contact information)Hope that helps!

Use your best friend Google to find real estate investor meetup groups. 

There are a lot of different ways to scrub a call list though, so I'm sure you can get more tools for handling that through this forum or a google search. 

One quick shortcut I've sometimes used in the past is to do a Google News search on the specific neighborhood the property is in, and see what kinds of stories come up. 

I’ve thought about googling GCs and offering them a small incentive ($50-$100) to offer me a ballpark figure that I’d be able to reference once I send the properties to my buyers.

It's worth a google/call. 

When you advertise on google, the leads come to you, and not the other way around.

(You may also want to search google with the keyword BiggerPockets, the results algorithm on Google is better than the one here on the BP website...if that's their biggest flaw though then they're doing something very right in my opinion :-) ) If you can't find the answer to your specific question in the blog / forums than by all means post up your question for feedback. 

You can search for these programs in Google.

Having trouble finding a link, even google is letting me down.