You can't price FA-56 parts at some of the other privately owned sites that offer better prices right now. Probably due to the changeover from the FA-56 to FA-56B.
I noticed that a the price of a new 91 is the same as what I paid for a new 125 when they first came out.
That doesn't seem to apply to Advantage Hobby. SAI6509 is $12.06 form Advantage, $15.68 @ HH.
http://www.advantagehobby.com/26746/SAI6509/
http://www.horizonhobby.com/products...-jj-kk-SAI6509
I seldom buy fron HH. Advantage is cheaper & you only need $50 for free shipping.
I did just buy the last two FG84 pistons from HH for $11.75 ea though, but I think that was a pricing error! Too bad they didn't have 3!