I personally only offer 30 minute meetings to return clients, however, sometimes things click and sparks fly on a first meeting... kind of like that KY Intense commercial. There may be no reason, really, to stay around and talk other than to laugh at the fact that the girl, quite frankly, blew the guy's mind due to his lack of expectation... no harm no foul... right?
So you book an hour at $300, you only stay 30 minutes and you need to get on with your day and you are giving me back 30 minutes of my time to lay out by the pool, read a book or just have some "me" time. I'd give you $100 back and only charge you for a 30 minute session. It's about time spent, not about what happens in that time period... period.
To quote a slogan from Max's Wine Dive...
"Fried Chicken and Champange... Why the hell not?"