Vegan or plant-based diet is basically fruits, vegetables, dals, grains, nuts and seeds. You can make all your meals from these ingredients at home in a very cost-effective way. In fact, most Indian vegetarian food is vegan. You do not need readymade or packaged foods. Dairy, meat, eggs and other animal source products cost much more and by removing them from your diet you are anyway bringing down the cost. Since your health will improve you will also save on doctor bills and medicines.