Could you add the ability to sell a ball instead of just deleting it?
The sell price could be relative to how many bricks that [exact ball] had broken.
Like if a ball broke 100 bricks it could sell for 10% of original price or 1000 bricks it could sell for 100% of original price and 100000 bricks 1000% of original.
So if I had a ball bought for $100 and it broke 1000 bricks when I sold it I would get $100 but if it broke 500 bricks it would sell for 50% so $50