I don’t know where OP lives, but for the vast majority of people in the world, it’s cheaper to cook plant based meals than eating meat, eggs and dairy foods. The exceptions is in places that have poor access to fresh food. But even then usually rice and dry beans is the cheapest food and very shelf stable.

The main reason it might be hard to pull off is if OP is not able to cook due to lack of skill, time, space, time. Many people end up depending on frozen meals or cheap take out because they have 2 jobs or something. But if you have time to cook and access to a supermarket, there’s nothing hard about vegan cooking.