The cost of a new helmet can seem kind of expensive.

But brain damage, employment loss, earnings loss from brain damage and head trauma, lifelong severe headaches, vision damage, skull damage, hair follicle damage, skin damage, hospital bills, and IQ loss are far more expensive.

You do the math, and get some good lights for night commuting. Halogen or ultra bright high-intensity LEDs in combination with a bright flasher or safety light in LED.