Economical Vegetarian?

Both articles spoke about the ethical and health vegetarians, and how many vegetarians identify with one of these categories. I agree that these two types of vegetarianism are the most common, but I would be interested in a third category of economical vegetarian. I would define an economical vegetarian as a person that has become or stays a vegetarian to save money. I found it interesting in the articles that the cost of being a vegetarian was never discussed. There may be factors that people stayed a vegetarian because they realized that it was cheaper. It would be interesting to find any correlations between staying a vegetarian and the amount of money you pay for food.