It probably depends a lot on the design of the arm, and the available tooling etc, whether a longer arm tube is very difficult for the manufacturer to make. Clearaudio Universal is an example where the price difference is reasonable - the 12” version is less than 10% more in msrp compared to the 9”. But the 9” is more versatile as it can also fit on the fixed arm board models like Ovation and Performance DC.
Graham Phanom is another arm with a reasonable/small price increase on the 12” version.
The Triplanar price increase sounds sadistic.
Graham Phanom is another arm with a reasonable/small price increase on the 12” version.
The Triplanar price increase sounds sadistic.