Why Do 12" Tonearms Cost So Much More Than 9"?

. On the other hand, I am a cheapskate so won't be buying one.

Thanks Lewm!
Gave me a good chuckle there👍😂

Lewm, The brilliance of the LT is that it is using the energy from groove friction to drive the arm! Friction pulls the horizontal bearing platform forward and a magnet underneath makes sure it maintains the right position. 
Uberwaltz, I am not entirely sure but I think the alto is a version of the CB.
The CB is as good as a pivotal arm can get for several important reasons. 1st is the vertical bearing is at the level of the record which limits warp wow. 2nd is it is a neutral balance arm. You can draw a line from the center of the counterbalance through the vertical bearing right through the center of the cartridge. Most other arms are static balance arms which always try to fine one level whereas a neutral balance arm will stay where you put it and won't start bouncing. 3rd. It has a brilliant magnetic anti skating device. No friction. 4th it is not a unipivot and has excellent bearings. Need I say more?

Is it wrong to just relax and listen,to your system....just Cill out.9" arms =12 " arms...Why spend so much money as still not be happy.At least you can afford  it. DO Worry Be Happy....

Lingo, Yes, it is wrong for a true audiophile to be happy, ever.  Now you've figured that out, you can become a member of the club.  We meet with Dr. Kevorkian once a month.

If you look at Ikeda tonearms the premium for a 12 inch tonearm is less than 10% of the price

IT-345CR1   9 inch arm (chrome) $6,900
IT-407CR1 12 inch arm (chrome) $7,400