Made this last night, it turned out well & only costs a few bucks so I thought I'd share.
I made it in the crock pot, but would work just as well on the stovetop.
BUDGET SOUP (christened during dinner)
4 potatoes, peeled & quartered
5 carrots, chopped
4 zucchini, chopped
1 onion, chopped
1 head garlic
1 tsp dried basil (or oregano, or sage, or whatever you like- I had basil)
1tb olive oil
chicken stock, 32 oz (large can Swansons)
salt & pepper to taste
Prep the vegetables. Heat olive oil & butter, saute onion & carrots for 10 minutes or so. Add the rest of the vegetables, stock & seasonings. Bring to a boil then simmer until everything starts breaking down, about an hour on the stovetop or however long you like in a crock pot set to 'low'.
For the garlic, chop off the top 1/3rd, exposing the cloves & simmer with soup, removing before serving. If you don't mind an extra step its easy to squeeze the cloves out, mash them up & add back in as an extra garlic boost.
When it's cooked, whirr it all together with an immersion blender (or a real one, but it's messier & more annoying) season with salt & pepper & serve. I classed it up a bit with a dollop of full fat plain yogurt topped by a sprinkle of minced parsley & a few passes of grated parmesan cheese.
Appended by a couple of crusty loaves & a salad, it fed four to repletion with no leftovers. Cost of ingredients was certainly less than $10, and you could knock a few bucks off that if you're a crafty, plan-ahead sort who makes their own stock.