I seriously doubt you will find them used - and, believe or not, I think it is a good value. These are offered by a member here and on their website,
www.fordgtbilletparts Many years ago Kelvin (AlohaGT) wanted me to get a set of these for his Heritage. I literally berated the hell out of Kelvin. "This is a waste of money." "Completely overpriced!" "A fool and his money are soon parted." etc. etc. Ignoring me, he told me to shut-up and order them. I did. They arrived. OMG. Pieces of art. Each machined from a solid chunk of aluminum. That bastard, Kelvin! A few weeks later I ordered a set for my car.
Nice stuff, GREAT fit. Worth a try, but I just can't conceive of anyone parting with them!