Side note first, on the cost of growing potatoes--the only cost is for the seed potatoes (and your time, but it isn't a particularly labor intensive crop). You can get seed potatoes from seed catalogs at a price I find shocking--but I buy a 50# bag locally for about $23, and if I don't plant them all I eat some. Potatoes are full of nutrients and store easily all winter in a root cellar--and we eat a LOT of them, so I grow as much as I can, usually running out about planting time in March. I do buy sugar, which is after all cheap--but we also boil down maple sap, and every three years I grow sorghum. Here are a couple of points on sorghum: there are three or four kinds. Some are short and intended mainly for the grain; some get nine to thirteen feet tall, with grain on top but plenty of sugar in the canes; some are for making brooms. So be sure you get seed for the tall sugar-growing kind. The plants need a fairly long growing season but tolerate drought and poor soil well. Cultivate like corn, which it strongly resembles until the corn makes ears and a tassel on top, while sorghum makes only a big plumey tassel on top, which turns from green through gold to a deep red and is indeed very pretty. In the fall you whack off the canes and the seedheads, using the latter as chicken feed or grinding it for gluten-free flour. But here's the catch--I don't believe there is any practical way of extracting the juice from the canes unless you find someone with a mill. I did, and he lets us bring our cane and run it through on the days he's doing a much larger amount (it's wonderfully romantic, all his kin are there and a few men are pushing the canes through a chugging 1920-era mill while down the slope more people are running the sap through a big evaporator pan, fed with wood, and the smell of woodsmoke and sorghum syrup is in the cool October air). Then you take the pails of sludgy green liquid and boil it down. With maple sap, you just tap the tree, while you have to grow and cut the canes for sorghum; but maple sap is boiled down at 40 to one while sorghum is about nine to one, However it takes a lot of skimming to get rid of the green foam--eventually it becomes clearish and a reddish gold. It looks like molasses (and here in WV people call it molasses) but it has a very distinctive flavor of its onw, a flavor that suggests mineral nutrients to me.