There are many reason to eat a vegetarian, or modified vegetarian diet. I first started primarily for environmental reasons (for example, less energy and resources are used to produce one pound of grain protein than is required to produce a pound of beef). Some have religious or cultural reasons. (I used to aim for strict vegetarianism during Lent, and modified mostly vegetarian otherwise; some religions forbid eating of certain flesh foods or all flesh foods.) I also started avoiding pork after getting food poisoning from a pulled pork barbeque sandwich while pregnant. Those sick days are not easy to forget even years later. Yet, somehow, eating one bad shrimp only kept me away for a few years until my allergy testing proved that I hadn't developed an allergy to shrimp.
I didn't mind the health benefits of eating primarily a veggie diet, yet now, I know it's a critical factor in managing my health. My main diet-related health concern is for my heart and circulatory system (also for my hypoglycemia). My younger brother's had two strokes before he turned 40. My father's had several mini-strokes, as had his mother, and his father died of a blood clot in his brain (his brother from both prostate cancer and a heart attack). My mother's had several heart-related issues, bypasses and such, as have her siblings; her oldest brother died of a heart attack in middle-age? or younger? I forget now, other than he was shoveling snow, not uncommon in Maine winters. As I age, it seems more acceptable to some that I eat vegetarian for my health. I still have borderline high cholesterol levels, it's hereditary for me, yet I also have high levels of the good fats. This could be saving my life (combined with exercise, yadda yadda).
The potential cost savings in health care costs is one of the cost savings listed in this CNN article I found on msn. Another is that the costs of purchasing some of the (non-prepared) vegetarian diet foods are comparably cheaper than the cost of meat protein foods. Of course, prepared vegetarian products (fake frozen sausage, for example), cost more just as other frozen/prepared meat products often are, imho.
Basically, if you're looking to cut your grocery costs, consider replacing a few meat-based meals with meatless entrees and meals. Assuming that you're still including sufficient nutrients, which isn't guaranteed in any diet without watching it, your wallet and body may thank you:) Besides, peanut allergies aside, how many of us who grew up in the U.S. DON'T like a good peanut butter sandwich once in a while? Okay, I admit, I eat it by the spoonful, sometimes adding sugar-free jams. And I enjoy "real" food, too, such as Thai food which isn't listed in this article. We're born omnivores, sure, but not carnivores. There isn't really any need to consume flesh foods in every meal.