An artist asked the gallery owner if there had been any interest in his paintings on display at that time.

"I have good news and bad news," the owner replied. 

"The good news is that a gentleman inquired about your work and wondered if it would appreciate in value after your death.  When I told him it would, he bought all 15 of your paintings."

"That's wonderful," the artist exclaimed.  "What's the bad news?"

"The guy was your doctor."