No. $5 or $10 won’t be better. It is called a boot. A boot for your tire. Useful information for any ride, not just the century. We will have SAG butprobably not too many new tires, so knowing how to boot a tire might save your ride.
Best bet? Don’t start out for a century on old rubber.
Even Family riders may won;t to take note, though. Unless you want to walk a chunk of the route. Be prepared.