Many years ago I paid $35 to a B&B member for a fine looking Gillette Slim. It's a great razor at that price and shaves well, I would never sell it.
Having said that, I probably use it an average of once or twice a year. The Wolfman is my daily driver. So I definitely prefer the modern razor, but I see no dichotomy in using the Wolfman and appreciating the Slim in my den. And for the budget minded, I would be amazed to find a $35 modern razor that was the equal of that Slim.
Slim is most probably where I would start if I had interest in vintage hardware. I learned to shave using plastic disposables and then onto cartridge kits so I do not personally have a nostalgic tie.
I have similar reservations. If I were to move into a vintage razor it would have to be NOS or completely refurbished. One would have to consider the immediate devaluation of course when using NOS.I don't mind vintage steel because it's honed anyway, but there is no way i am buying a vintage DE/SE razor unless it was NOS. Shaving is very personal and i avoid buying things that were used on someone else's face (or who knows where).