When I first discovered 6 in 1's a few years ago, I ordered them from Escalon directly. Their product and shipping charges were very reasonable which was less then a grocery store price of 28oz can of S&W or Hunts.
I now buy 6-in-1 canned tomatoes at a Costco Business center, City of Commerce in California. They only sell #10 can, for approximately $3.25
. Restaurant Depot in Fountain Valley, CA carries 6in1's also.
If you have a Costco Business center around, it's worth checking them out. Your regular Costco membership grants you access there too, it's not just for business memberships. Note: Business Center hours are different then the regular Costco wherehouses, usually 8-6 and maybe closed on Sundays.