Well, IMO it depends what your canning and why..I use to can dozens of jars of tomatoes.I don't anymore. I not really on a health kick, so now i buy canned tomatoes when i see them 10 cans for 10 bucks, the bigger 28oz cans.With the price of cooking gas, the time you put in, the cost of a canning jar, its not worth it to me.Now if cans of store tomatoes skyrocketed it may be worth canin my own agian.If you want the satisfaction of doing your own,and controling whats in the jar, then yes, thats another story, but its not cost effective.I don't can veggies, i don't like them that way.However i do can chicken, salsa and items like that as some others here have mentioned.Canned chicken isn't really cheap to buy.I keep mine up to 3 yrs, i'm rotating out the 2008 jars that will be three yrs old this Nov.If i can buy cheap in the supermarket, i do...Ten cans(28oz) of tomatoes for ten bucks is a good deal, they last on the shelf for three yrs. Are they organic.? no...They stock my pantry and give me something to work with,chowders, soups, sauces, etc..and will last on the shelf for three yrs,thats good for my SHTF plan...I can things that are expensive to buy in the store.I use to can my own tuna fish when i could get it dirt cheap in the '70's...Now the stuff is like gold..! So i buy solid white albacore tuna when its 10 cans for 10 bucks on sale, last three yrs on the shelf.Even if you got hundreds of canning jars for free, the gas or electric and lids to do the job, are expensive these days.IMO, only certain things are cost effective to can.In the good old days of cheap jars, cheap fuel, it was a different story.Now if you had a outside wood cookstove, and access to free firewood, and cheap/free canning jars, you'd be geting much more cost effective...