They actually cannot do anything since the cant intervene in marketplace.
I can feel how the game is slowly dying, many people left, I left few months ago, now I am playing again and the ms for 1.2m (blue server price) is crazy, I am lucky cause I can afford many, but I understand that new players cant pay that much, when I started playing the price of ms was 80k/120k and for new players even 75k for the bike is a lot...
People should stop buying ms from other players, that's the only solution in my opinion
Edit: if bosses started drop ms as a random drop the price of medallions would decrease, second possible solution