Its been a min since I have actually seen any of the fader banks for sale, however if my memory serves it was around $200 per bank, and a little more for the bank that included the master fader (17 - 24 + master)
I know the AIO cards right now are hovering around $275 per card, DIO cards $100 ~ $150 per card. (Don't ask me why, but I assume because there is just more of them out there than the AIO cards)
At the time when I was seeing the fader banks for sale, I wasn't really in the market, however now I am looking for the 17-24+ Master fader bank because although touch input of my ch. 18 fader is recognized, the fader motor itself doesn't work, and outside of that my console is in perfect condition, and my OCD just finds that a glaring issue. lol.
Buuut... now I cant find a single fader bank for sale.