Hi Aelyrsenn,
You got some good advices here. You really should check links on this forum posted above and other topics ( Life without bread and Ketogenic diet particularly ).
I live in Croatia, so I know what are you talking about food prices and incomes. I think it's much cheaper when you start to eat that way - if you stop buying "evil stuff" like processed foods, pasta, bread, dairy, fruit... And how is it easier to cook that way. You do not need to eat much steaks or other expensive parts of meat.
I started with this diet 2,5-3 years ago and lost 17-20 kg till today, looking and feeling so much better that I can't express it. Mostly, I eat pork belly (carsko meso) or other fatty parts of pig, bacon, cracklings (čvarci), sometimes eggs, with little vegetable, lettuce, or any of that, with vinegar. And bone broth! I'm still not at zero carbs just trying to cut carbs (from vegetables), as much as possible and to increase fat as much as possible. After a while, I needed smaller and smaller amounts of meat to satisfy my hunger. Bone broth really helpes in that.
I just tried to do the best with what I had. I cant find grass fed and organic pork or beef meat, lard or bones (only sometimes chickens and eggs), and that was in the beginning my big concern, but the results are still very, very good and obvious, so far.
I buy meat and bones (pork or beef bones - 4 to 7 kuna/kg) at the local butcher shop. Sometimes you can find bones with a lot of meat. In that case you can buy it more and freeze it. Also, you can buy cheap entrails (liver, kidneys, heart, stomach-„tripice“, etc.), or pork leg and skin. You can do liver pate, it is very tasty and a good way to get enough fat. I found lard at domestic producers (not grass fed) in the nearby villages (12-15 kuna/kg).
As everybody here pointed out, bone broth is very important and cheap way to get valuable nutrients. I cook it once in a week or two (I cook it 10-14 hours because I do not have pressure cooker), divide it into small bottles and freeze it, so I always have it at my disposal.
Just try to do the best with that what you have or can get.