All of the above have given you some great ideas. Anytime you can buy and cook large amounts of roast beef or pork, chicken thighs or breasts, etc do so. Freeze meal size portions and then nuke when ready to eat. If you are still in induction, the veggie thing is easy - a cup or two of lettuce, a cup of green beans, some spinach, or turnip greens.
Try to watch for specials at the store. And, ground beef is usually fairly inexpensive. Form it into patties and freeze or cook the patties and then freeze. Nuke the amount you want at a meal.
Almost every day for lunch I have a ground beef pattie with mayonnaise (not Miracle Whip), maybe a slice of cheese, on top of a handful of lettuce. Basically a cheeseburger without the bun.
Eggs are usually a good value. Wal-mart generally has the best price in my part of the country.
All this meat can be expensive compared to beans, rice, and potatoes but - if you were doing colas and snack foods before, you will probably see a decrease in your food bill.
Good luck!