Invest now, save later

Get yourself a nice, big, deep freezer. After the initial investment, having a big freezer will pay for itself in no time (especially if you are prepping meals in batches of four). You can use this wondrous applicance to store food in bulk, which enables you to pay less per pound of it at the market. Even better, you can store lots of meals prepared in advance, enabling you to just go home and pop something homemade (and therefore healthy and cheap!) in the oven instead of reaching for that take out menu from the local Thai place. And you'll finally have someplace to stash all the turkey stock you made after Thanksgiving.