The first Cid was an airship pilot, a quality he shares with many of the others
6 Holo, reverse holo, or non-holo A holo (shiny artwork) is almost always worth more than the non-holo version of the same card
Yes, there were players who splashed a second colour for utility and sideboard cards but before Sling-Gang Lieutenant goblins stuck to the consistency that a mono-coloured deck offered
#3 Slow Going Now we hit upon another one of R&D's little rules: Discard happens at sorcery speed
Shining cards are tough to pull and highly valuable and collectible
There are a couple of genuinely fun pre-constructed decks in the rotation, and the game throws cards and gold at you for every little random accomplishment, so I could see a lot of Arena players having a perfectly successful run with the game without ever sinking a real dollar into it