15M might be okay, if replay type was set to Auto. Way too low for Fixed. I would put it back on Auto. If the customer complains, explain to him that you set it back to default settings and give him a few free credits. (then thank him for playing your games d:^)
Check your earnings audits closely. Especially free game percentage and average ball times. If the replay percentage is high (over 20%) and average ball times are more than 1.5 minutes, they're getting their money's worth. LOTR typically has long ball times and earns well. 75 cents a game, 3/$2 is reasonable for clean and working LOTR IMO. No matter where you are. Average games of 5 or 6 minutes is probably about right for LOTR. Any more than that and the wear on the game isn't worth 50 cents a game.