The local Sam's here sells Interstate 6 volt for around $60.00 a peice. I'm not sure what they're getting for the 8 volt. Around here Sam's in about the cheapest for golf cart batteries...
I bought 8V batteries from SAM'S and they were a couple dollars more than 6V. Be sure to take some old batteries with you I think their core charge was about 12 or 13 dollars.
Finally made my way out to SAM'S today and they have the 6 volts for $65 and the 8's are only a few dollars more at $72 each. I was expecting to pay a lot more. Way2go SAM'S.
Now how do you fit 12 8 volt batteries into the back of a Honda Civic?