I've bought batteries from Costco and found their prices to be quite competitive. However, in your case you might want to check out the Interstate Distributor in your area to see if they have any "blemished" batteries. These are batteries that were not sold by dealers and returned to the distributor due to age. The distributor checks the batteries before offering them for sale, which is normally at a little more than 1/2 price. I've bought several from them and have good luck. Our distributor is in Lynnwood, south of Everett.
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