That's exactly it!
I was a bit surprised by the prices these things fetch, but since mine is fully serviced and comes with a 12-month guarantee... that's different from finding one at a garage sale that may or may not work.
Well, if it's an Aerometric model, the one you find at a garage sale actually has a pretty good chance of working after it gets flushed out (the 51 Vacs may need some restoration work, but I have three of them -- two of which were "sumgai" priced, and I was that "sumgai" ).
I found one at an estate sale about 5-6 weeks ago which turned out to be a rarer color Aerometric (Forest Green) and all I had to do was flush it out. Okay, now the pliglass sac is stained from the ink I used to inaugurate the pen (vintage Quink Permanent Violet)....
And yes. They just... write. All the R&D work went into making 51s what they are -- superb writing instruments. No, they're not gonna fiex (although if you're lucky you might find one with an oblique nib). Yeah, some people complain about not getting to see the nib -- even though they understand the reason for the hood). Deal with it. Or send them to me or to mitto (nah, send them to me -- he's got hundreds of them already... ).
Ruth Morrisson aka inkstainedruth