As of approximately the date of this post, I found the following battery heavily discounted...

Prostart Platinum Premium Lead-acid Automotive Battery
Part # 151R335PP SKU: 402673 (I'm told the actual SKU number is 0402673.)
Prostart Platinum Premium Lead-acid Automotive Battery | Product Details | Pep Boys

Reg. Price$134.99 / ea
Sale Price$69.70 / ea

They apparently have discontinued the Platinum batteries, at least in this size.. I was able to call a local Pep Boys and they were able to look up in the local area of other stores who had it in stock...

When I got to a store that allegedly had it in stock, they actually didn't have it in stock, even though I had called in to double-check to make sure they had that size/type of battery in stock.. so they were kind enough to offer me a different brand at the same price.