I don't actually understand why missiles are so expensive. You can buy an off-the-shelf turbojet engine for $1,000, and cheap toy drones are equipped with sophi

I don't actually understand why missiles are so expensive. You can buy an off-the-shelf turbojet engine for $1,000, and cheap toy drones are equipped with sophisticated guidance electronics. I'd have thought it shouldn't be hard to build a cruise missile with INS for under $20,000.