@JoeW I don't think that issue is unique to arena. My roommate has a similar issue in Cockatrice where opponents will just leave if they see a card they don't like or that signifies a certain deck archetype they don't want to play (eg. Tron, or Ponza)
The MTGO economy is basically a mirror of the real world MTG economy, including the ability to buy singles from third parties for real money
And it has a set redemption system, which allows you to exchange a full set of cards in MTGO for the same real set. Because of that, the prices actually track real world prices, to an extent
Looking at possibly getting back into the game but don't want to start dropping money on cards before I can get a better feel for how everything works these days