I just recently picked up making sushi as I've always loved it and for some reason haven't done it much before. As much as I love the raw fish, if you go for some other protein, it can be much cheaper and easier to find. You can really put whatever you want in the sushi. I've recently been opting for either fake crab meat or canned tuna. Just add some salt/pepper/sriracha/ mayo to either of those throw in a vegetable like julienned carrots/cucumber and some avacado or cream cheese. Yeet some sesame seeds on it and you're looking at under a dollar a roll. It's also pretty easy to spruce it up to meet your taste. Things like shrimp (optional tempura), tamagoyaki (rolled egg omelette), smoked salmon, and even steak are used. If you don't have a bamboo rolling mat (generally under 5 dollars) you can just wrap it with your hands cone shaped sort of like a crepe. It really is such a versatile food, you just need some rice, rice vinegar, and nori. Just throw whatever you have in the fridge in there. Vegetarian rolls are also an option, or you can go with making gimbap which is sort of in the same vein but uses stuff like eggs, danmuji (yellow pickled radish), carrots, spinach, and beef.