Great Britain - Penny black and Penny blue

The iconic Penny Black and Penny Blue, with the well-cancelled Penny Black showing some traces of the red Maltese cross, and the Penny Blue seemingly unused but it contains a very light line (almost invisible) which makes me unsure whether this stamp should be considered stamped or unused.
Stamped ones are already highly priced, certainly the Penny Blue; for an unused specimen the catalog value is enormous.
The stamps are already going on sale at what, in my eyes, is a very low minimum price.

P.S. no shipping to the USA