Not only on the island but also in most local areas are asked this question. I can say YES and NO.
YES, the house rent or land rent cost almost nothing compares to a city like Tokyo. Instead of that, we should pay for the fare for the ferry every time we go out. If you live in the city, you don’t need to have a car, because you can go everywhere by train or bus, or there are car-sharing services, but most inhabitants of the island have and maintain at least 2 cars by 1 family because we need one on the island and one on the mainland. I’d say also NO.
NO, there are some stores and you can buy food, daily necessities but they are a little bit more expensive than these goods that you find at the supermarket on the mainland because the transportation costs are put on. YES, people give me foods like onions which they grow up in their field, fish they catch, fruits that their family sent. Sometimes I can prepare all free dinner.
Going out to drink or eat is cheaper, so YES. I used to go to Italian restaurants or some ethnic diners in Tokyo, drink a couple of glasses of alcohol, share some dishes with my friends, then when I pay, I feel like “Wow, we ate and drunk that much? I was thinking paying less…” Now the situation is completely opposite. I often feel “I was thinking I’d pay more!”
There are a few places to go to eat or drink on the island. If you want to eat a hamburger, you need to go to the mainland, I don’t think you may eat a double cheeseburger set which costs 640 yen paying 1100 yen for the ferry, but this is the option. For hamburgers or some nice Chinese meal, you may eat on the way to go to the clinic or shopping. However, if you want to eat churrasco, you of course have to take the ferry and drive 2 or 3 hours. You spend not only money but also time. To enjoy various types of food, NO.
Sometimes online shops tell me to pay more for carriage, NO. The insurance of the car you use only on the island costs less, YES. When I drink with elder people, they pay all for me, YES. The neighborhood association fee is expensive, NO.
There are a lot of reasons for YES also for NO. The most important thing is staying here is comfortable for me.