I remember a radio phone in a few years ago. They were discussing modern art and had a modern art "expert" in the studio.
Some guy rang in and said how he thought most modern art was rubbish. He said what was to stop him putting a load of bricks on top of each other and calling it "art"
The art expert in the studio said "it would not be art because you are not an artist"
So there lies the rub.
If I left a load of dried baked beans on a plate it would just be washing up.
If Tracy Emin or Damien Hurst leaves a load of dried baked beans on a plate it is art and someone will pay �2000 for it.
So if you want to make lots of money from modern art, first convince people you are an artist.
Then put together all sorts of strange items, give them pretentious names, discuss them as being "a thought provoking study of the 21st century in relation to climate change" or some such rubbish.
And charge �1000 for each of them.
It worked for Tracy Emin.
http://www.tracey-emin.co.uk/