Hey Mick.....I would like to order one of these but $650, holy #$%*e!
Stev-o, I appreciate not wanting to spend the money, but I will say this: the amount of work that goes into making a swing arm of this nature is enormous. The time spent welding alone you would pay nearly that much for someone to TIG it together. Then of course you have all the other fabrication and machine time (lathe to turn the pivot tube, milling for the axle keepers, Cryo treatment afterwards, etc). If you use $50/hr as a base rate, I bet there's nearly 35 hours of work in these. I'm making a couple of swing arms from scratch, also from aluminum, and I can attest to the work and time and "touches" just to get one thing dead right.
At $650, they are a bargain for their quality. Maybe not what you'd want to spend, but outside of CMR and TTR400, I don't know of another modern arm being made for the CBs. Spend it, you can't take it with you!