If you want to raise the rarity of an item, slowly seize control of the majority of that item. Now, as the demand is still there/goes up, the supply will go down in the public atmosphere and you now control that item in the economy. Congratulations, you've won the game.
:0 Challenge accepted
Live your life, enjoy it while it lasts. Don't give it up when you are down, you are a light like the stars in a sky.