Terrific topic and, in my case, timely as I recently had to answer a relative who asked why I needed "another" brush
My answer was:
We all have a certain amount of money available to us.
Some have just a little bit, some have a huge pile and most have something in between.
Once we have allotted for the basic necessities of life: food, a roof over our heads, basic clothing and shoes, maybe a car, some insurance and have put some away for emergencies and retirement and the kids education...
what's left is what the experts call "disposable income."
We each spend our disposable income on what makes us happy (or what we think will make us happy.)
For some.. that might be a new car... or nice clothes... or handbags or shoes or golf equipment or a country club membership or new living room furniture or kitchen tools or plants for the garden or some yarn for knitting or a new camera or a laptop computer or an iPhone or a kayak or a pretty bracelet or some candles or a new bed for your beloved dog or a DVD or a used piano or a beach chair or ........
I drive a 13-year-old car because it still runs great and my mechanic says we can keep it humming for another 5 - 10 years and spending my limited pile of money on a new car would not make me happy.
I don't spend money on fancy clothes or jewelry or shoes or handbags or any of that stuff. I live in t-shirts and shorts or slacks. Nothing fancy.
But I'm retired and I have hobbies... so that's what I spend my disposable income on.... Watercolor paints, paper and brushes and instructional DVDs. Yarn for knitting. A subscription to ancestry.com to do genealogy research. And a gym membership so I can stay healthy as 70 approaches.
And I buy good watercolor paints and paper. I buy good brushes.
Why???? Because I want to

and I can.
I like working with good tools. I love the surfaces of Fabriano Artistico and Arches paper to paint on. I love the colors of Winsor & Newton and the consistency of Maimeri paints. I love my Escodas and DaVincis and Raphaels and Pro Arte brushes. They make me happy just owning them. They make me happy when I use them to paint.
So I'll keep my 13-year-old car and buy me another brush
Tred, enjoy all of your beautiful art supplies !!!