Webinars can be hit or miss. The New York Adventure Club, due to the obvious difficulties of getting out these days, have some on offer. I took in one on Five Points that was excellent, and there is one on July 21 about the Brooklyn Bridge that I have signed up for. $10 isn't too much, I guess, though I'd rather do tours on foot (boy I miss the Urban Hike and I hope we can pull one off in the Fall...I was thinking of focusing on movie locations this time).
If you're interested in spending an hour and learning about NYC's history, here's a great way to do it. Just click the link and see what they have to offer.