@xenu01 Yep, it helps the jam set. As I understand, the case for it is that it produces a thicker jam without having to cook for very long or use as much sugar. So in theory, the result can be more fresh-fruit-y (having been boiled only minimally) and take a bit less time. This sounds good to me, though I admittedly haven't done a lot of with/without experiments.
I wanted to try the whole canning thing this year, but I'm cheap and lack storage space for a huge cauldron. So... it turns out you can process jars perfectly well perched on a vegetable steamer (which cost me maybe $4 when I couldn't find my old one) inside an 8-quart pasta pot (which I, like most people, already own). That's minus about $110 of your fixed costs, though admittedly in exchange for having to spend a little more time putting the jars through the water bath since they don't all fit at once. Pectin is still expensive, though!