A CGC certified .5 of Detective Comics #31 with cream to off-white brought $3,400 when the buyer used the eBay Buy It Now option. The copy was noted as being incomplete and missing the back cover. The copy had a very minor amount of glue on the front cover, and also eight pieces of tape on the cover.

This key issue of Detective Comics not only featured a classic cover, but also significant for introducing the Batplane and the first appearances of the Monk and Julie Madison. The CGC Census notes 42 copies certified with the highest graded example being graded 8.0.