Is upgrading seats worth it

[NibbaTyrone]

I always buy the large seat upgrade but Is it worth it

[Toxcatl]

Upgrading seats reduces time and cost required for the stadium upgrade, and you don't lose anything in the process. You can do these upgrades one by one, from the smallest seats to the biggest one.
Generally, it is better to do all other upgrades first, and only after that seats, and after that the stadium itself. Do not spend tokens on this.