". . . continue to pursue this? . . ."
As a new Licensee, what activities is it competing with, or will it displace something more important ?
Go and meet the Man and seriously look at his Property . . . . look at it through your eyes; and then try to see it through his eyes. Where is reality ?
Is it really the "diamond in the rough" that he's seeing ?
How many projects has he started and not finished ?
Is this one the one that is actually closest to being marketable ?
Some people are very good at identifying viable projects (and even starting them; but they can't finish anything; and they never develop an "exit strategy" !
You'll meet up with many flippers, and attempted (failed) flippers, in your career. You may as well meet this one and develop your sense of empathy for his and similar situations. Examine the motivation; study the finances; look at the Zoning; evaluate the prospect for sub-division. How desirable is the Neighborhood; and what are the Comps that he'll be competing with ?
In this business, you can't help everyone, even when it's really interesting, and if you don't smell money (for you) you just can't get involved. You have to separate the wheat from the chaff.
So go and learn from it; evaluate the situation, and hone your skill in expressing your professional thoughts diplomatically to someone who probably has his own opinion and doesn't want to hear anything to the contrary.
Remember, straight advice is in very short supply these days, and a guy like this may still be a valuable source of Referrals in your future. One or more of his other holdings may one day be an attractive Listing for you.
I don't want to portray him as thoroughly pathetic; and there is plenty for you to learn from him . . . . "There, but for the Grace of God, go I" !
Just because you visit with him doesn't mean you must take the Listing . . . . I've walked on many a listing because of outrageous expectations, personality incompatibilities (as hard as it is to believe, some people just don't like me!), or a variety of other issues that made them a poor fit.
I have to enjoy what I'm working on and enjoy dealing with the people I'm trying to help. Life is only some 27,000 to 30,000 days long, so if it ain't fun, I don't do it; and you can't help them all.
Now I digress. Good Luck !