The Price and Quality thing
The final price to the consumer is a percentage of the manufacturing cost. So if a shock costs $20 to make, the wholesaler buys it for $30-$35 and sells it for something like double, or $60-$70.
If it costs $30 to make, the wholesaler pays $45 -52.50 and the consumer pays $90-$105.
So the consumer is paying $40 to $50 profit for the cheaper one and $60 to $70 for the item that costs just $10 more to manufacture.
If course, with a shock the major cost or pain in the butt is the labor to install it, which is exactly the same for a KYB as it is for a Bilstein. The company knows that the average car will be sold within 3 years and a good percentage of the purchasers that don't sell, will have lost the receipt, rendering the item much less likely to cost them anything for the warranty. In this case the extra money might easily be worth it, particularly if you tend to keep a car forever, (well, 5 to 12 years or more).
I can't say anything about KYB shocks, because I have never had any. I am very happy with the Bilstein HD's I installed at 120K on the 1990.
The rear suspension of my TE wagon is a lot harder when going over speedbumps than the 2.5 sedan. The load leveller works as it is supposed to, and on the highway both cars feel about the same: very stable and responsive.
Semibodacious Transmogrifications a Specialty
1990 300D 2.5 Turbo sedan 171K (Rudolf)
1985 300D Turbo TD Wagon 219K (Remuda)
"Time flies like and arrow, yet fruit flies like a banana"