No. Medals are PROOF of your valor (supposedly) to the royalty of the game (whatever the backstory is, IDK).

How do you TRADE medals? You can't trade valor.

The only suggestion I've ever seen on this discussion that makes sense is greater value medals can be used IN PLACE of LOWER level medals. No other solution is allowable IMO.

PS. Yes, you can get medals from the store. I consider those bribes to the congress/royalty of the game.