It's the increasing complexity of the products that seems to be driving the cost upwards. Implicit in my comments is a belief that linestages really shouldn't be that complex a device.
I don't necessarily think it's the increasing complexity of the products that drives the cost up. After all an Audio Consulting Silver Rock is at minimum $13k, and no one is going to convince me the passive Silver Rock is a complex linestage.
However, I'm in complete agreement with the second sentence. It's the reason I now favor passive linestages. To me simpler is better and passive linestages are among the simplest designs. In comparisons I've done with my Slagle autoformer and Lightspeed attenuator (which I have compared to the Silver Rock), both hold up very well against more complex and/or costlier designs.