I would NEVER do something like that. It is really no different than buying a box of baseball/football/whatever and getting a common auto of some scrub who warms the bench. It is not OK to "modify" that card to suit you just because it is crappy. While Mr. Adams and I frequently end up on opposite sides of arguments, I could not agree with him more in that what is pictured is indeed the definition of "sketch" and anything above and beyond that is a bonus.
That being said, there have been vast changes in the "sketch card" hobby to get away from the 15 second repeat-a-sketch quality that some folks turn in..and that is a great thing. I would also like to see some type of quality control by the manufacturers...if an artist's work is not up to snuff, reject it. If the same folks turn in poor quality repeatedly, do not have them back.