I usually buy Smuckers brand No Sugar added jams.
I know they are made with concentrated grape juice as the sweetener (so, sugar, but let's not get hung up on *words*), and depending on the flavor (and where I buy it, i.e. Canada or the US) it's about 20 calories per Tablespoon.
It costs 4.99 for a 310ml jar. (that's $0.0161 per mL)
So I finally decided to check out OTHER jam. I wound up sticking to the double/triple fruit kind, because as I looked through the labels, I saw right away, regular jam, OMG, high calories! That stuff is pure sugar (or high fructose corn syrup... don't get me started).
Back to the comparison.
The Smuckers brand Double Fruit ALSO has 20 calories for 1 Tablespoon, has sugar in place of the grape juice, and that's about it for differences.
However, it costs 4.29 for a 390ml jar. ( that's $0.011 per mL)
And my store's own "healthy" line (the labels are blue, and are always less fat, less sugar, less sodium, than the competing brand)-- a 500ml jar of "twice the fruit" strawberry for 3.99.
And it's 25cal per tablespoon.