Yes, looking at the batteries can be confusing.
Four years ago, checked out Sam's and Costco batteries.
Local Costco only carries golf cart batteries in the summer here. (checked each year since)
Costco wanted me to pay for all 8 batteries + core + tax and pick them up once arrived, not willing to call me ... (two batteries in stock)
Sam's had non standard batteries, couple bucks cheaper, after doing the math decided not a good deal. 189ah vs 225ah (typical golf cart battery). Later did find a Sam's with a real golf cart battery.
Beware of 12v golf cart batteries, what I see is rated at 90 to 110ah, less than half 225ah. Cost is more than 6v battery. (When I looked $57 vs $70) . To hit a voltage need half the batteries, yet the savings is not half. (capacity is half) I wonder if the 12v are as durable as the 6v. Most 12v are marine batteries, not the same thing as a golf cart battery which is a deep cycle battery. Make sure what you get is deep cycle. See batteries labeled deep cycle / marine. To my knowledge they are not the same thing as a real golf cart battery.
Moral of the story be aware of what your buying and know what you want! (and verify what your getting)
Have fun,
Scott.