While the metal cards cost quite a bit today, I wouldn't make any offers for them (even though I was tempted by the Hurloon Minotaur which moved within the last year) because it is reasonably easy to make fakes of those, and the questionable quality of the originals makes it hard to tell anyway.

I'm going to seek to correct my mistake regarding the efreet soon. It's going to hurt the wallet. :(