Is sparking in the motor of my drill a concern?
If the motor has brushes some arcing is normal even with high quality equipment, cheaper models usually have more arcs that are visible because the armature is usually rougher. You may notice a decrease in the quantity of arcs as the brushes seat to the armature, I regularly dust my brushed motors with dry compressed air to reduce buildup and on big motors. Usually higher voltage this reduces the chance of flash over that can do a fair amount of damage. + for both comments.