Money Score
Money score is the score out of 200,000 you achieve on a song and is the basis for high scores in arcade mode.
Unlike the Japanese games, Beatmania US shows the money score in the grade up window, instead of the traditional EX score.
The term "money score" comes from the fact that in the early 5-key games, your score was called "money", presumably to represent the riches you make as a DJ. Many people still refer to them as this, even though it's not been referred to in-game as such for ages.