Well most raw vegan food is already way cheaper that raw meat:

Quality organic dry chickpeas, lentils, beans, soy etc… already are around 2€/kg where I live and when you add water they double/triple in weight so you end up at 1€/kg. You’ll probably eat a bit more weight than meat but still the price is nowhere comparable. Add some whole cereals instead of white bread for nutrition and better satiety: they’re more expensive but you got the price back on the quantity you eat (you won’t stuff yourself that much T165 bread or brown rice: the fibers will make you feel full super fast). And for the vegetable you usually can find stuff super nutritious for cheap : apples, leak, cabbages and alls sorts of oignons.

Even fancy organic quinoa is like 10€/kg but also double in weight and you only eat ~1.3 times the meat weight you’ll eat in meat-meal.

Industrial chicken is 5€/kg un the shop and "good" one 15€/kg. Quality beef is nowhere in that range.