A interesting sidelight to this story is the next closest Sears is 35 miles away.
Here is the Sears extended warranty
Road Hazard Plus Protection Agreement
The Road Hazard Plus Protection Agreement entitles you to expanded warranty coverage against non-repairable tire damage beyond normal wear and tear, including road hazards experienced under normal driving conditions. It includes mounting, inflating and balancing of the repaired tire, or a replacement tire, with a new valve stem as described in the Agreement. It also includes a 25% discount off the regular price of an alignment when your tire is repaired or replaced under the Agreement. This agreement is for 4 years from date of purchase. Protect your tire investment with Road Hazard Plus Protection Agreement. For complete and detailed information about the Agreement, contact your local Sears Auto Center.
It seems the tires are about $150-160 new. If they believed there was not a mfg defect then $50-100 per tire seems fair to me. If it was a defect then Sears would be off the hook and BFG would be.
BFG warranty
HOW REPLACEMENT CHARGES ARE CALCULATED
Workmanship/Materials
A tire which becomes unserviceable due to a condition covered by this workmanship and materials limited warranty will be replaced with a comparable new BFGoodrich® brand tire, free of charge, when 2/32nds of an inch (1.6mm) or less of the original tread is worn, (or 25% or less, whichever is more beneficial to you) and within 12 months of the date of purchase. The cost of mounting and balancing the tires is included. You pay the cost of any other service charges and applicable taxes.
When more than 2/32nds of an inch of original tread has been
worn (or more than 25%, whichever is more beneficial to you) or
after 12 months from the date of purchase, you must pay the costof a comparable new BFGoodrich® brand passenger or light truck replacement tire on a pro rata basis. The retailer will determine the charge by multiplying the percentage of the original usable tread worn by the current selling price at the adjustment location or the price on the current BFGoodrich® brand Base Price List,whichever is lower. This list is based on a predetermined price intended
You pay the cost of mounting, balancing, and any other service charges and applicable taxes.
Mileage Tires
A tire meeting the conditions for treadwear pro rata
replacement will be replaced with a comparable new
BFGoodrich® brand tire based on the actual mileage received.
The participating BFGoodrich® brand tire retailer will determine the charge by multiplying the percent of mileage received by the current actual selling price at the adjustment location or the price for the new tire in the current BFGoodrich® brand Base Price List, whichever is lower. This list is based on a predetermined price intended to fairly represent the actual selling price of the tire. You pay the cost of mounting, balancing, and any other service charges and applicable taxes.