Two pairs of black Carhartt cotton duck overalls I bought in 2010 and 2011. One knee is blown out but they are the softest most comfortable clothes I own. I still wear them once or twice a week, wash on hot, dry on hot. These, a Dickies pocket T shirt, and 15 year old 14 eye steel toe Docs are the 'uniform of the day'. Other than a few nice suits and some shorts, I'm pretty much not interested in clothing. The suits were bought for corporate recognition and I work from home otherwise.

I'm going to say my $50 charcoal grill. I've had more propane grills fail on me in 5 years, and charcoal grill keeps going. I know its terrible for the environment.

A bicycle. No gas to pay, no parking fees, no insurance, and I can do most of the maintenance.

• Epson Ecotank Printer

Has ink tanks so money isn't wasted on cartridges and the printer is actually initially expensive unlike those printers that make money back on ink catriges

• Hammer Drill with the proper bits

Makes it easier to mount shit to bricks, goes in brick like butter if you're using the right drill and bits

I recomend Ryobi Hammer Drill & Bits

• Air Fryer

I've stopped using my oven and only use it rarely for things that I don't want blown apart thst I can weigh down with a fork or spoon like Pizza for example

• Refillable Japanese brand pens and mechanical pencil

I recently got these to aid in Japanese study and refillable pens are more economical in the long run

And Japanese brands go hard on the quality of stationary and I got introduced into the cult of stationary obsession with this

I'll edit my comment if I can think of anything else

Camping hammock, it's what I sleep in most nights. My body complains when I have to use a mattress

My Casio A 168 - I like watches and typically I would opt for more expensive ones but I still marvel at the amount of watch you get for this kind of money. The design is great, very comfortable to wear, very precise and has a very good battery lifetime and background light.

Someone else already mentioned a safety Razor.

My iron pan - much healthier, more ecological and will last longer than I will ever live.

Obviously my bike. Saved so much money on it. Although I still need to figure out what I should do with my very rusty chain. Should I replace it?

I bought a big pack of eneloop rechargeable batteries a decade ago and they are just within the last year or so starting to fail.

House insulation.

I live in Australia where the minimum insulation required by law is a long way below inadequate, and many cheap contractors go below the minimum because it's so hard to prosecute them.

I already had solar and a house battery, so the next obvious step was replacing the insulation. With my already very low electricity bills I cant say that it literally paid for itself (although it would have without the solar and battery), but it has made the house so much more comfortable. On some summer days, the AC would be using 7kW and barely keeping the inside temperature down to 30°C/85°F. Now it uses 3-5kW and the whole house stays comfortable.

Also, finding and patching the massive gaps from the previous "landlord special" house extension made a huge difference to the temperature of that room, and explained how lizards had managed to get inside.

Used Wacom Cintiq 21UX I got off FB marketplace for like $300 (MSRP went for $1500+) about 5 years ago. No new drivers are being updated or released for it because it's so old, but it still works great. I've likely made back what I paid for it in art commissions since then.

50ft electric plumbing snake. Cost $60 and saved me $200+ bill first time I used it. I've used it for friends and family as well, making its value well over 10x in savings, not just my own.

First thing that comes to m8nd is my Pitbull head shaver. I s(h)aved several hundred euros on simple head shaves, 2 minutes a time.

My radar detector (Valentine V1 Gen2) literally paid for itself the first time it alerted me of a speed trap ahead. I am guessing it has since saved me 10's of thousands of dollars.

When you are replacing a water heater, always get the biggest one possible. Nothing is worse than being the second person showering, and you run out of hot water halfway through. It used to happen to me every day.

Then we had to replace it, and a bigger one wasn't that much more. I asked myself if it was worth $100 to never have a cold shower again, and then got an even bigger one than that.

Haven't had a cold shower since.

Battery charger.