If you play online poker, there is tracker software available that will tell you exactly how much money you spent per day. It could be several Bitcoins per day. 
What about other casino games? I will play sports betting and some slot games like dice, roulette and other. If I want to know how much amount I will play for these games, i want to maintain one record. I don't have that much time, and I will not play daily. When I get free time, i will use my extra money and play. So I don't know exactly how much I will spend coins.