RE: how much you will pay for it?
If the 19.8 lbs thrust is from the ThrustHp chart, forget it, it's way high..
MY G26 tested with at Mejzlik 18-6 and Abell muffler at 9000 gets 17.5 lbs thrust with a scale on the tail wheel..
Put yours on a plane with that 20-8 at 6400 and see what a spring scale reads...