While it is good to get batteries from locations that are easy to get to, NAPA/Wal-Mart and the like. Especially if you are prone to abuse the batteries. Why spend a lot of money on batteries that won't be properly maintained and end up having a shorter life. Also, most places are not going to stock RV batteries, as these are very different than what is needed for car starting batteries, Cold Cranking.
There are a lot of places that sell good RV batteries and include shipping in their pricing. That is what I would go with, unless you wish to have the serviceability of local business. I would check with Bestconverter
clicky on their prices and types of batteries. You should be able to check sizes on their web site too.
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