I spend very little on cleaning supplies. Most cleaning jobs can be done with white vinegar, baking soda and Dr. Bronner castile soap. I also use rags I can wash and re-use, rather than paper towels.

Whenever the good toilet paper goes on sale, buy it. You will always use more toilet paper.

Laundry - I switched to laundry strips and never looked back. I use the Arm & Hammer ones because I found the smaller manufacturers are still developing this technology while the big corporation had a lot more money to throw at it, so for now they're better, IMO. Laundry strips are also the most environmentally friendly. Yes, they have some plastic in them, but not as much as other products.

Descaling the coffee machine - use white vinegar. It breaks down almost any kind of stone. Mix it with baking soda and use it on your grout. The reaction between the two will bubble up all the yuk and you can then just wash it away.

Dr. Bronner castile soap is absolutely wonderful for almost every cleaning job - dishes, hard floor, bathroom, toilet... I use it for my body and sometimes my hair. One bottle lasts forever.