Tire warranties -- good idea?

[rodster]

New Toyos should be here Tuesday. The tire dealer is offering a $53 per tire, lifetime of the tire warranty. For that they'll replace any tire that can't be fixed no matter if the tire was damaged on or off road. I don't know for sure but imagine that any warranty payoff will be prorated for wear.

Maybe I'm missing the point of this great deal but for what I'll pay for warranty for 5 tires, for less than $100 more I can buy a tire if one gets trashed.

FWIW, the majority of the miles these tires see will be offroad.

Anybody have advice? Thanks for any and all suggestions.