The Millionaire Center is the very large low building with the MC on it, located in middle left Centropolis. The prices of items range from the very lowest 5,000 sP to the very highest at 400 million sP. This shop does not bargain, prices are fixed. You are only allowed to purchase one item every hour. If you try to purchase an item sooner, you will see an "Oh no!" message indicating how much more time until your next purchase will be allowed.
Items used to come and go seasonally, or permanently appear or disappear (usually with a News announcement), however on June 21, 2015 it was announced in a news post that people can buy items from the off-seasons for a higher price. The current season is displayed at the top of the page as is the percentage increase in price for off-season items.
There are some legendary weapons and exclusive color potions sold here. Everything available from the MC is exclusive to this shop and can only be bought here or from other user who first bought them here.