Edit: so it turns out that every hobby can be expensive if you do it long enough.
Also I love how you talk about your hobby as some addicts.
Fountainpens. Started with some cheap Chinese pens. Now I have multiple vintage pens and a Montblanc that I love writing with.
Would I be correct that this hobby, if it’s not just having a nice thing for everyday use, does it eventually lead into: calligraphy, fancy stationary, special vellum papers, custom wax stamp seal kits, grinding your own ink, etc?
Vell naturally.
Rhodia paper FTW!
Then it might bleed out in mechanical pencils, sketching, drawing, painting, general arts …
Or just getting your hands on that really really nice colored P200…