" but I don't see how that could continue if the trend continues and the w/p 10 is 40k."
Not so sure that I understand your logic.
With progress and innovation there always comes price increase to go with the R&D which established it.
I remember back in the mid 70's when the cost of a Mercedes 450 SL was considered to be absurd at $15K. The new SL550 has an MSRP of $90K.
"such a price for such a small speaker"
Don't kid yourself that this is a small speaker. The soundstage which it throws is spectacular