As I have noted here (archived) before, I have been exporting full sheets of 1¢, 2¢ and 3¢ stamps in bulk to Europe for many years (1990s) in exchange for jetons. Every time I bought sheets in bulk (80% face) it was the same story from dealers: too much trouble to exchange for face (1¢ stamps in exchange for 1¢ stamps) and then trying to use them for postage. I mostly bought full sheets, too.. and when incomplete, I'd exchange for face.

JB