In a couple of months I'll become a student and have to be stricter with my money. What should I prioritize to buy to get the most nutritional value for my bucks? Eggs of course, green leafy veg, coconut oil, avocado are staples, but maybe some liver too? And meat/salmon? Berries/nuts - maybe not that important?
What about buying conventional produce and using a washing liquid like Environne ?
I think I would consider giving up grass-fed and organic before giving up some food groups, and before that try to reduce other expenses.
Keep in mind you get less nutrition per pound in conventional meat and produce, but your budget may speak loudly. Consider keeping in touch with some game meat ranches for some game, or taking up hunting (maybe bow hunting? You might not catch as many, but the season is longer and if you catch just one deer, you're set)... also consider learning to fish. Even sunfish are tasty, easy to catch, and found everywhere. Free food is always good. Keep in mind that in most places "non game fish" don't have a limit, may be easier to catch, and might be tasty... also some counties allow the use of a simple net.
Best way to be Paleo on a budget IMO, become a hunter/fisher, and join a fraternity or sorority so you can grow some veggies of your own at the house.
Try to get some liver, sardines, egg yolks (you can even throw out some of the whites). If you're able to use a crockpot, you could get whole chickens and turn them into soup easily, and then use the bones for bone broth; you could also use it to cook cheaper, tougher cuts of beef and turn them nice and soft and tasty.