1 N555 timer= 1 dollar.... 2 resistors = 5 cents.... I Capacitor= 25 cents... 1 relay= 2 dollars. Total = $3.30..... With my circuit you can vary the flash rate by changing the resistors. You can draw any amount of current by using different relays. you can use either LED's or real light bulbs if you choose. With automobile flashers, you can't use LED's because LED's don't draw enough current to make the flasher operate. If yours is so simple, your not too getting much for your 5 bucks.