This is a funny comment about this particular piece of art because it is an obvious & unsubtle reading of the theme of this piece (and other Banksy pieces).
I think the obvious & unsubtle reading above makes a ton of sense. It is a critique of the modern art business for sure.
But also it seems likely that the auction company was in on this so I sort of read it as a statement that you cant separate the business of art from the making of art.