One hint I was given, when you need to buy so many of one item, just buy a couple and put them in storage and get them back out. Each time you put it back counts as buying one. Thanks for the other hint, wish I had seen it before finishing pt 3! Oh and some of the rare animals give a lot of food when you feed them. Yellow and green turtles (but not blue!) lynx, reindeer, can't think of the others. Also almond trees, white peach, plum and raspberry bushes. I just make sure I harvest/feed those each day. And I have decided to ignore pt 4 of the canning mission. Just going to keep collecting food, cloth etc and not check to see where I am!
One more - the black deer that you save give 35 food when sold and the owls give 100!