When looking for groceries, check out the Lidl chain of stores. The assortment is small, but the prices are really lower than in the most popular K-Market, for example. Especially there you should look for branded Finnish chocolate — it costs much less than in the manufacturer's coffee shop, which breaks our pattern of "direct - cheaper".
There is such a magical thing as free food distribution in Helsinki. Several times a week, supermarket products that are almost expired are brought to a couple of points. They give them away to anyone who wants them — a very practical action. Don't hesitate to look for current addresses and days — Finnish products are of extremely high quality, and remain so even at the end of the expiration date (and rumor has it that even after it's over, but we haven't checked).
On one of the days, be sure to have lunch at the Market Square. It has the most authentic street food, where they'll mix up at least 3 kinds of northern fish for you. No, it still doesn't cost a penny because it's right in the heart of the city, but it's still cheaper than a café and way too romantic. At the end of the day, let's be fair — the portions at Finns are great and the food is really good. Save on anything, but be sure to have a sandwich with the freshest salmon or a soup with salmon. Because where else but here?
Conclusion. Bring something basic like tea and coffee with you. Eat breakfast at home and feel free to walk around with your lunch. Look for the cheapest products at Lidl and the freebies at special distribution points.
Speaking of cafes, remember the golden rule of the traveler: "The farther from the center — the cheaper".
How to save on entertainmentThis is
another question that you need to ask in advance. And Google will give you the answer to it — Helsinki Card. We have already written about cards of this type here. They are available in many European capitals and give the tourist excellent benefits.
In the case of Helsinki you can choose a card:
1) for an adult / for a child;
2) for 1 / 2 / 3 days;
3) for free visits to more than 25 attractions and discounts in many locations of the city, including popular cafes and souvenir stores (MOBILE) / all previous options + free travel in the capital (CITY) / all previous options + free travel to the regions (the intersection of three zones) (REGION).