What is judged to be valuable art?

Uh, actually I think everyone has a different perception of 'valuable art' but here is my take on valuable art.
Valuable art has to have a concept or idea behind the artwork. I think if it is anything less than that it will just be mindless work. It has to evoke some thought (a new insight towards a certain situation perhaps) to the viewer, only then it can be considered as significant. It could reveal the artist's intention.
Secondly, the artwork has to have an aspect of originality. This is a minor quality to define valuable art however this is vital. I mean one can't possibly replicate a work (lets say the old masters) and expect to sell as well as the old masters. This aspect correlates with the previous factor.
Valuable art includes artwork that have a long lasting attractiveness to the patrons. Some call it 'investment' and others call it 'collections'. Whatever you call it,it can't be appeal for a short period of time. Think Mona Lisa. 200 years! :)She is still considered valuable art.

Okay correct me if I'm wrong?