I live in an individual room in a very cheap apartment shared with roommates. It's close to work place so I don't own a car. I go grocery shopping with a colleague who has a car. And I split the gas traveling to and from the store with him.
My work place has a gym and a coffee bar so I get my daily coffee/ drinks & gym for free. I pay for my meals though.
Workplace provides supplies and amenities so I don't have to pay for a lot of them. For the amenities I do need to buy, I try to either use store brand ones or see if friend/ colleagues/ roommates have ones they don't want and willing to give me for free.
These habits puts my spending on necessities to be less than 1/2 of my salary. Counting other sources of income, it's about 1/4.
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Now, for the diving part:
I am still a recreational diver right now, but about to go into tech.
I still need to rent a van to go for local diving since my buddy also don't have a car. But I figured it's cheaper than owning that depreciating asset.
I have a single cylinder set up except for the tank. Stilled accumulated them on the secondhand market. Most are barely used. I usually look for gears that are too cute/pinky for male divers to buy. So I got them at a good deal. I don't keep extra gears around. If I get a new mask, the old one has to go. But often I can sell my used gears for a tiny profit or at least very little loss since I always get them for good price.
For non-local dives, I try to get dives on my work travel. That don't always ensure good dives, but they give me more experience with different conditions. And beyond that, I try to group my dive trips with road trips with family & friends.
