Cooking vegetables is cheap, healthy and delicious, but can be labor intensive at times. Firstly, I would recommend making vegetable stock from scratch, instead of bullion or store bought stock. Its super cheap, super easy, and you can make a lot at one time and keep in in the fridge for a while (or freezer forever). All that is required to make stock is put some vegetables in a pot (use the cheapest ones like onion, carrot, celery, garlic; none peeled), with some salt (and herbs, if you want to get fancy) and fill the pot to the top with water. Boil for 30 min, then strain. Done. Its the base for pretty much every good vegetarian soup or stew.

My favorite red colored soup is a spicy, cheap, vegetarian version of borscht. 1 apple, 1 onion, 1 pepper (1/2 of a bell pepper if you don't want too spicy, or 1 hot pepper if you do), 3 beets (peeled), 3-4 mushrooms, 6 cups stock, cumin, salt, pepper, lemon juice, and herbs that sound good to you or that you happen to have lying around.

Chopp all the vegetables, apple and mushroom very small. Cook them in a large pot with 2T butter and 2T oil for 15 min, covered, stir every few minutes. Add herbs and spices, cook for a minute or two. Add stock. Bring to boil, then simmer for about 30 min, covered. Done. (Traditionally may be served with sour cream, but I think its fine as is.) Insanely delicious. And probably cost ~$8 to make a meal for about 4 people.