I bought some at
Battery Systems - The Single Source Solution!
in Sacramento a few years ago. Go great service when I had a problem about a year later.
Bought them in Sacramento, serviced and replaced them in Riverside.
I am a big fan of Costco, but have not had good luck with their GC batteries. Replaced one batch (Six Batteries) in less than a year and the replacements are still not up the Trojans. Seems like they have a high internal resistance and the voltage drops more that it should under a light load. When fully charged, I can use the microwave and the voltage will drop down to 11.5 volts. Didn't drop below 12V with four Trojans. My electrical need have changed considerable and I will go back to four Trojans when I need new ones.
'01 National RV Tropi-Cal, Ford V10, '01 Suzuki GV 4X4 Blue Ox Tow Bar,300 Watts Solar, 2500 Watt '458' Inverter, NO TVs, Most light fixtures upgraded to LEDs