You're right.... There's always the vintage option for 14K nibs! Not that I get hung up on steel vs gold nibs, but I do use it as a consideration of what I'm getting in return for what I am paying when it comes to an NOS or vintage purchase. Take for example our fairly recent discussion re: the Platinum big cap pen with steel nib vs the Pilot Elites out there... you helped me see that the value just isn't there in the Platinum big cap model, unless there.
You hit the nail on the head: My love for the solid color Balance PNB-3000 is because of color and thickness. It also was the first real Platinum pen I had used (Preppies and Plaisirs don't count in my book), and I fell in love with the buttery nib, which was as smooth as my Kaweco Dia broad that cost more than three times as much.
The reason I have seriously thought about replacing the basic blue Balance is because it is a pen I both truly enjoy and that I can comfortably leave at work without losing sleep over it getting lost, stolen or broken by someone "borrowing" my pen. A $50 value is the upper limit in terms of what I feel comfortable leaving behind. Vintage and NOS pens do not fall into the leave behind category, unless they are ubiquitous and easily replaced, such as the Pilot Elite and Reform 1745 (I also am noticing now that they are only halfway to my $50 limit; I don't think I'd leave an Estie behind!).
I have been looking at the PTL-5000 and 10000 on Engeika's website, and am impressed with the price-value proposition they offer. I could see myself with a red one. And if I loved the steel medium nib on the Balance, I am sure I'd be drooling over the PTL-5000's performance. The PTL-10000 seems nice, too, but I don't know whether I, ham-fisted as I am, would personally be able to appreciate a quality difference over the 5000.