I wish you lived near me....I bought about 80 dozen Kerr/Ball canning jars quarts and pints for $1.00 a dozen a couple years ago. I was teaching food canning and preserving classes at church and in the community so needed lots of jars to send home with some of the students. Each student got a jar of whatever we canned to take home with them. Like everyone has said, mayo jars should never be used in a pressure canner. Extention Office says ONLY can in Kerr/Ball jars but I've been canning for years and did use mayo jars for all those years and had good luck...an occasional broken jar but usually had good luck. Enjoy your canning!