Over the past 30 years, I've had interstate, diehard, Motorcraft and GM batteries, none have lasted more than 5 years, some as few as 3, most die (they can no longer start the car) between 3 and 4 years. Domestic American batteries suck!Just because something cost more doesn’t automatically means it’s better.
Last summer, I replaced the original battery in my Cayman that had been in there since February, 2013, over 7 years, and it hadn't yet failed to start the car. I replaced on age alone.
So you will likely buy 2 batteries in the time I purchase 1, genuine, Porsche battery for not much more coin.
No, higher cost doesn't mean better, but lower cost doesn't mean equal either.