The Hokuriku pass isn't bad at all for the difference in price of a nice meal or two. At the minimum, you won't have to keep figuring out the ticket machines or booths except for seat reservations.

From Tokyo, you could use it to day trip back up the Arch to Karuizawa and other onsen areas using the same Hokuriku Shinkansen. It can also come in handy if you encounter issues at any point that might compel you to move around, or if you need to retrieve things.