I believe that the blue mason jars are collectible unless thet're those new Ball jars that were put out in teh last ten years or so for crafts or to use to package bake goods in.
Are they wire bail?
I have must be over 50 wire bail mason jars that if I really needed to I'd put in rotation but only for high acid foods like pickles. Bought new rubber rings when a feed store was going out of biz as I orginally planned on pour candles in those jars.
If they aren't your thing you might try selling them to fund buying modern canning jars.