There's cheap frozen veg too. The problem is largely variety and texture.
It isn't that good reasonably priced vegetarian and vegan lifestyles aren't possible. The problem it's when you set "cheaper than animal products" as the bar to get under, it becomes very boring very quickly.
I do limit the amount of animal products I consume myself, and unless everything is in season somewhere somewhat local, I don't find myself saving a ton of money.