Typically, extra labor -- that is rewarded -- for an art piece is going to be something that is pertinent for some common end.

Using Windows 95 to paint something doesn't add anything to the end of a piece.

Using marble and creating a structure that looks like a fluid river (or flowing something) adds value to the piece even though it was hard.

Using marble, period, adds value simply because the work is in marble (monetary value) and represents a skill that you can produce works of art in marble. Using Windows 95 means you can use dated technology to produce literally the same thing that Photoshop CS6 could product (most likely in less time): a JPG.

It literally is the same difference as painting a scene with your hands, and then doing it with your feet. Nothing was added and the work is no different, but you did it with your feet.