I just finished canning some pickled zucchini and figured I would pose the question here, is canning financially worth it? Here are some of the costs:
Main ingredient being canned: For this batch, it's zucchinis from our garden. There was cost for the seeds to plant, but they were minimal ($0.10 packet) and I'll be using the seeds in the future. I was watering them often with rain water, but found out I was over-watering so I just let them be now. They did take yard space, but if I had grass there I would have had to mow it.
Vinegar & Spices: I used about 1/2 bottle of vinegar (2 cups), 1 cup of sugar, 1/4 cup of salt and a bunch of spices. The only free spice was dill that I grew from seeds from last year's plants. The other spices were peppercorns, mustard seed, and celery seed. The costs there I will estimate at $1.50
Jars: I picked up a 12 pack of jars for $4 at Menards last week (that is the price after rebate). I used 4 of the jars, so the cost was $1.33 in jars (they can be reused though in the future).
Heat & Water & Equipment: There is the pots, the bowl that they sat in brine for a couple of hours, water, etc. No easy way for me to measure the costs but I consider them minimal.
Time: My active time canning consisted of 1/2 hour total (cutting, preparing brine, canning).
Overall my financial costs this year run about $3 for the 4 jars of pickled zucchini and 1/2 hour of my time. I know the jars can be reused, which if one estimates you can reuse the jar 5 times before they break, the cost comes down to a little under $2 for the 4 jars, not counting my time. If we counted my time like I was at work, the jars would have cost $12 more ($24/hr I get paid).
Overall, for me the cost doesn't matter. I'm not doing it to save money, I'm doing it to have food I know where it came from and can't buy anywhere else (eg: How many stores do you see selling pickled zucchini?). Am I crazy to think that way?