Keep costs down by eating at markets and camping
Finland isn't cheap, but there are methods to minimize costs and save a few dollars. This is definitely one of the top Things about Finland You Should Know. Make lunch your primary meal of the day, since many restaurants and cafés provide a good-value all-you-can-eat lunch buffet with soups, salads, and daily specials. Most large towns also feature a kauppahalli (covered market hall) where you can get picnic supplies (bread, cheeses, deli products, smoked salmon) and feed at one of the snack stalls or cafes.
Camping is a low-cost mode of transportation. Most campgrounds are great, with cottages for rent and lots of space to pitch a tent - but they are often only open from June to August. Though you don't mind foregoing a hot shower, you can wild-camp thanks to jokamiehenoikeus (everyman's right) – a terrific (if risky) choice in a country with 41 national parks and nearly infinite stretches of nature.