People seem to go modified keto or paleo when 'done' losing weight.

Going back to a SAD type diet will make most people fat again. I get that your food situation may not be ideal in the future. I wouldn't be planning for high carb ever again though.

Sam even on a tight budget you can do keto and in fact would probably be cheaper. Remember the basis of a ketogenic diet is that your body switches from burning carbs to burning fat. So fatty foods are better and give more energy AS WELL as more filling. This means you can buy the fattier i.e. cheaper meats etc, not to mention eggs/bacon with a side of veggies is a darn near perfect keto meal. Many people who are keto adapted only eat 1 meal a day with maybe a couple of snacks so that lowers your overall food cost too. In my house we have 3 people eating keto (well 1 full core keto the other 2 eat carbs sometimes outside the house) and my food costs have actually gone down almost 25% from the carb heavy days. If you go into it thinking that you won't be able to do it...then you won't.
Here are some things that should be relatively cheap and keto friendly

eggs
any meat, ask the butcher/meat department guy for the cheapest cuts..they don't always put them out in a showcase and they are just as good if not better on keto.
veggies (stick to the green ones)
Spam (if they sell it where you go to school)
pepperoni/sausage/deli meats

If you inbox me where you're going to school I'll do some quick research on things you can get there to try and stay keto.

Olive oil and butter on EVERYTHING. Canned tuna with oil/mayo is really cheap (can even class it up with celery and spices), and you don't really need the bread if you just eat it out of a tupperware container. Like everyone else said too, eggs are super cheap. Get in the habit of making deviled eggs every few days. Steamed broccoli with butter and cheese is a fantastic dinner.

Funny, I took biochem. I would think someone else who was taking it would understand basic premises. Like not having carbs equaling insulin sensitivity. By your logic, if we stay reaaaally far away from germs, then we'll become resistant to them. HAHAHAHA.

Try "The Art and Science of Low Carbohydrate Living", it explains how low-carb dieting is used to treat metabolic syndrome, and it's easy enough for anyone to understand. I hope.
Now, I think I know what you're talking about. You're talking about being on a very-low-carbohydrate diet long enough that your muscles resist insulin spikes so as to spare glucose for use in the brain? Because that's entirely different than the insulin resistance that SAD diets induce, causing metabolic syndrome and type II diabetes.

As far as calories go, being in a caloric surplus on a ketogenic diet is better for muscle preservation and even growth. It takes longer, because muscles like insulin and carbs for building, but it's possible. I usually eat at a caloric surplus ketogenically and I've lost about 45lbs so far. Tell me that's all water. It's even somewhat beneficial to do it that way because your body likes to hold onto it's fat stores (again, basic biology) and it will sacrifice muscle to keep the fat. If it has enough fat coming through, it's like "hey, i have enough dietary fat, i can lose some of this body fat. And hey, look, protein! I can build up some muscle because this dude's been working out!"

Bump.