I agree that you should get more for four single chips, than for a set.

But if I see a set of four, seperate, I won't bid on any. Why would I want to win three auctions and be missing one chip? (and pay more)

I suppose the test would be for me to put up something reasonably interesting, one as a set, one group as individual chips, and see what happens. (although one test doesn't make a study!)

For the set you show, my opinion is sell as a set. If you had something else, like 4 Queens dogs, I'd sell them as individual pieces, so people can fill in holes in sets.