Many people nowadays are trying to save money wherever and whenever they can. Although car batteries are not relatively expensive, it is nice to save money where you can. There are many different brands, so the prices can vary greatly. Please note that prices vary on many factors. Such factors include, cold cranking amps (CCA), reserve capacity, brand, and size. Because prices can vary on so many factors I will try to use a baseline, a size 35 battery, roughly 700 cold cranking amps, and 90 minutes of reserve capacity to compare prices.
Interstate brands are only available at authorized dealers. For a size 35 battery with 640 CCA the price will come out to roughly $100 give or take. Reserve capacity is unknown and not stated on the official interstate website.
Gold-Duralast brands are only sold are Autozone. They give one of the best warranties out there for car batteries. A size 35 battery with 640 CCA and 100 minutes of reserve time will cost roughly $105.
Kirkland Signature can only be found at Cost Co. They can be found there for around $65. Not much information can be found online about these types of batteries but there is a variety of feed back from real consumers. There has been no negative reports about these batteries. Many users find them reliable and most importantly, dirt cheap.
Everstart is available at Wal-Mart. They are known for their low prices and low maintenance; however, there are some negative reviews. Some consumers claim they are great and others claim they have had problems with Everstart; nevertheless, they are still considered one of the top brands to choose from.
DieHard brands can be found at Sears. They can be bought for around $100 for a size 35 with 550 CCA and 100 reserve time. Again, these get mixed reviews from consumers. Mixed reviews are not a good sign because they mean that the product is not consistent. Although, it should be noted that this brand is rated good for its reserve time and life span.
Last but not least is Optima, which can be bought online from Amazon.com. This brand is one of the few brands that can be bought online. Prices vary from $130-$200. A size 35 Optima battery with 720 cold cranking amps and 98 minutes of reserve capacity on Amazon costs about $160. Optima batteries are more expensive when compared to other brands because of their name and reliability. There are virtually no negative reviews on Optima.
Now it is up to you to decide which brand will suit your needs.