Assuming linear pricing (which is not how it actually works, but is good enough for a rough estimate).
A 15.36 TB drive on CDW is currently $3k, Link
So a 122 TB drive would be at least $24k. Personally I'd guess closer to the $30k-$40k range.
This is a fantastic keyboard, I love mine.
Be aware however that it is the "previous" model, and still uses a micro USB port to charge.
G915 X LIGHTSPEED TKL is the latest model, and uses USB-C