I didn't read through the whole thread but I had two ideas for you ( apologies if one or both have been mentioned):
Cantor packeted tuna fish is always a great "go to" - it's healthy and very inexpensive. tuna is also very versatile... put cheese on it for tuna melt mixing with pasta and spaghetti sauce, lots of really inexpensive options. I lived off of that stuff in grad school
also rather than buying appliances try looking on your local freecycle list. you can either post "wanted" for what you are looking for, or just see if anyone offers anything you might need. for example on the Silver Spring yahoo freecycle site