Cheap protein sources to get bigger?

Hello, I’m starting calisthenics next week and my goal is to get a little bigger. I’m not thin I’m 1.79cm around 80KG I still have chest/biceps/triceps from doing calisthenics 1 year ago.

I did some research on what to eat and this is my following notes:

No junk food.

Eat lot of fruits and veggies.

Eat protein.

The problem is currently haven’t lot of money, I can only buy really cheap things. My cheap protein sources so far are: eggs,yogurt,whey protein , almonds.

Can you guys suggest me any cheap protein sources? Also if you have any tips what to eat to get bigger?

Also another question, can I eat 5+ eggs per day? I did a research but I’m kinda confused.

Thank you! :)

Cheap protein sources to get bigger?