There is absolutely no reason that going vegan should cost more than your omnivorous diet. But, chances are you WILL find yourself spending a lot more on groceries when you go vegan. Part of the reason veganism costs more is because you suddenly start caring about your health more. It is hard not to care once you find out about all of the creepy chemical ingredients lurking in your food (and vegans are constantly reading food labels, so it is hard not to see these ingredients).
Going vegan by no means has to be more expensive than an omnivorous diet. But, if you are eating convenience foods and/or opting for healthy organic options, then you will probably see a rise in your grocery bills as a vegan. To help you save money as a vegan, here are some places where you can get vegan coupons.