Fine idea on the plastic covering.
There’s another set with action markers (Bottle Cap series 2.0 listed by Pinebox above - Sun in Yer Eyes tokens etc).
Ouch on the import costs! I know a bunch of people picked the bottle caps up direct from Pinebox at Worlds 2018, but that isn’t a solution for everyone, but such indulgences are more bearable on luxury items at least (rather than eating this kind of charge on essentials like the cards themselves). They’re far from mandatory, but we used the fancy tokens this week and found them both fun and useful. 