One of the main ingredients of the rolls and sushi are the algae. Most often used nori. Without them it would be impossible to give the rolls a proper shape and hold the stuffing inside. Discussing the ingredient has a high cost. Actually there are several ways to save money and buy nori seaweed cheap.
First, get a very economical large packs. For example, package with 50 sheets of seaweed will be 1/3 cheaper than buying the ingredient in small batches. But this method is only suitable for those chefs who prepare sushi and rolls quite often.
Secondly, you can order nori seaweed on many Chinese sites. That's where they are much cheaper than in the Russian shops. For Asians it is a common cooking ingredient, which is not something exotic, so price it accordingly. However, the purchase will have to wait on average 3 weeks.
Thirdly, look for records of algae in the pharmacy. It is often in pharmacies in the cooking sections of supermarkets algae are sold at low cost, as a source of iodine. However, it will have to bypass several points to find the necessary goods.