Last time round all my grand theorising was a waste of time, so this time I'm keeping quiet, voting B, and hoping Frownland will choose some nicer pics next time.

A looks like a dime-store print, and B doesn't even look like it would make it into dime-store inventory. My gut is telling me that B is more expensive, because it looks as if it would fit the prototypical art-critic "these scribbles are so deep" motif. That, and like Janzoon alluded to, A is more like "A Starry Boat."

Going with B on this one.

Ex A looks like a paint-by-numbers kit. Jans & Aux-in are right, it looks like a knock-off van Gogh that you find in a five below store.

Ex B looks like photograph of scribbling on chalkboard by someone struggling with the Palmer Method.

Ex B impresses me more, because it looks more troublesome trying to reproduce something that mundane in oil paint than the dilettante attempt in Ex A. ... but because of the popularity of van Gogh I will gogh with Ex A.