The trick is finding an original. The one I found on Ebay was in a populated Tron panel that I paid $76 for.
To use the 49-way stick, you have to have a GP-Wiz 49 which appears to the computer as a USB gamepad. You can use this at the same time as the I-pac. The whole stick from 1up is around $80 plus the GP-Wiz 49 Max at $34.95 (also available in Eco for $22.95).
The Tron stick isn't the cheapest addition to your cabinet and it is also not the most used stick, but it is really, really nice for Tron, Discs of Tron, Zaxxon, and some other games. I am building a panel with two of these so I can also play Assault and Battlezone with semi-authentic Tank controls.