Bmx Ramps How Do I Make A Launch Ramp For My BMX?

How do I make a launch ramp for my BMX? - bmx ramps

The idea is 1 to 2 meters in length for my BMX ramp, all the others who sell online, very small and very expensive, so the question as a springboard for my BMX bike. Does anybody know a website that I can best, or what? THX: D