If you are interested in doing a search, search "property address search in NYC" and you can find Department of Finance Web App to find out Market Value. 

How do you go about finding those (any good web site focussed on new construction?)

They put it on the web!  

If you are looking for wholesalers, just do a web search “sell my house fast Plano” and you will get about 20.

There are plenty of tips and tricks out there but in the end for STR's it all comes down to creating a valuable experience for your guests....all success flows directly from that but you can certainly increase your bottom line by optimizing processes and reducing costs when possible.  

https://www.waynecountylandrecords.com/recorder/web/ so go here, create an account and search by the address of the property you are interested in.

I find info on the web a bit murky about this.

Finally, it provides sample letters you can customize and use.NOLO web site is a great resource for state law.

Current have a web site but the company apparently has gone out of business. 

Granted this is a deferred tax strategy vs an optimization strategy, but the end effect is pretty similar if you plan to expand your rental portfolio in the future and pass on to later generations.