In Korea, it is customary for prospective buyers to pay the extra money to the owner of any business establishment when they want to buy it. The more customers and nicer facilities any store or shop has, the more money the buyer has to pay in order to buy it as a premium money.
For example, there is a store which costs 100,000 dollars to build. For the first year, its business is slow. Several years later, the store gets to have so many customers and its business is really good. The owner wants to sell his store at a great profit when someone wants to buy it.
What do you call "the additional money" which the buyer has to pay in addition to the original cost "100,000" dollars?