Free play! Coin mech are just another thing to get jammed or create problems. I realize most people remember playing in arcades with actual quarters but this is home arcade. I would think that most guest would simply not play any games if they have to pay. Only a fellow pinhead would pay for a home use machine. I actually with Stern and other manufacturers would make it optional to have coin mech or just have dollar bill slots. It would save some money and labor to make games.