I got an expensive mattress and eradicated nearly all my sleep-related pain.
I have a few excellent fountain pens, fountain highlighters, refillable white board markers, refillable markers, a refillable rollerball, a refillable ballpoint, and a good mechanical pencil. I take good care of them and don't have to buy writing utensils anymore. The shape and weight of my pens also allows my arthritic hands to write for hours without pain. (Writing is part of my living, so this is a big deal for me.)
Our pots and cast iron were probably middle-of-the-road price, but well worth it. Some of them are 25 years old now and would be mistaken for new. They cook everything evenly. Well worth it.
I have hardbounds of my favorite books so they survive multiple rereadings.
I have an excellent quality hiking wheelchair. Tht thing will survive anything and is very easy to repair (or so says my brother-in-law who does the repairing). It was NOT cheap at all, and it requires arm strength I don't always have, but man... it's amazing.
I have a mid-range mobility scooter: light enough for me to take apart and put in my car (the heftier ones are too heavy), sturdy enough for my general use, and easy to repair.