Items on the pedestals in the secret rooms within pig ruins all require 1 oinc to take, as if you were purchasing them from a shop. It appears to affect all the pig ruins (or at least the 2 I checked). This issue has only presented itself on one world. All previous worlds, and a new world to test the bug did not present the issue.
Not sure how to reproduce. Brand new world, and no world settings were changed, but it could not be replicated.