Totally agree with everything you just said. 
I actually think the price is an absolute bargain!
If you have not looked at the costs involved with similar AR systems, you really should.
Massive one off fee’s or ongoing subscriptions (even on slightly crippled versions), pay per tracker impressions, mandatory watermarks…
Adams one off price of $249 is crazy good!
Yes, he uses a free opensource framework but he has worked hard to put it in an easy to use package for us shmoes. I always think of how many man hours this would have taken me to do if I attempted to create a usable, cross-platform plugin and I charge $56 per hour for my time.
is being a gift horse here. Be grateful or he may stick the price up. 