There is a lot of research out there that shows why art is good for you, and it isn't just because it's beautiful or anything like that. It's because art sends messages to our subconscious that cause us to react.
But it isn't just prints or photos either. According to a study by the Emory University School of Medicine in 2010 in an article by psychcentral.com, when people see original art they are more likely to activate the brain's "reward system" than if they looked at photos of similar objects in the paintings.
The subjects in the study were shown paintings and then shown photos of similar objects that the paintings had. It was found that more parts of the brain were activated when the subjects viewed the original art than when the subjects viewed photos, particularly that part of the brain that works with rewards, financial decision-making, your appetite, and impulses.
So what's the benefit here? Buy original art maybe you'll be thinner, make more money, be better motivated, and make fewer impulsive decisions.