I think that hell do just fine in the 99 of this precon as a reliable way to put bodies on board and dig for artifacts, but he feels a bit slow and durdly due to the fact that his Ultima Founding and Master of Machines abilities require him to tap as part of their activation cost
That ship sailed a long time ago
A Marnie CSR from S4a Shiny Star V has traded at $150+ for years because Marnie is a franchise-favorite character, while lesser-known CHRs can stay at $5$10 for the long term
There are plenty of ways to combo with Sidisi, giving you near infinite Zombies, mill effects, you name it
I own two Commander decks that are probably easily worth over $150 each, and have a few individual cards in my collection that are easily worth more than $20 each
If you want to know why, check down further below