"Do you think this dealer is correct?" No, but he's not totally wrong either. Vinyl intrinsically will continue to have collectability and archival value to an extent not shared by other formats, regardless of whether its audiophile worth becomes completely passe. The fact is that for the formative and golden ages of this era's defining musics, vinyl was the format of record (you can't buy puns that bad yet that appropriate!), and it's still anybody's guess when those musics might eventually be supplanted by something newer *and* more popular, if at all.
(The same kind of suspension of obsolesence may occur to a lesser degree with CD, since the current post-modern age of pop music [alterna-rock, rap, techno] has the CD as its format of record, and also because digital disk-readers of the near future will be able to handle all such formats right up until the entire breed quickly goes the way of the dinosaur in favor of data-by-wire. Since that will likely entail some kind of pay-to-play however, I can see many listeners continuing holding onto their silver disks for a good while afterwards.)
For his business of the high end though, I can certainly forsee the day when the current audiophile fad for re-acquiring or first-time-acquiring vinyl rigs and software cools back off considerably as digital distribution and storage really come of age - considerably, but not totally. When that time arrives, he may no longer want to be in the game, but others assuredly will, including those catering to collectors and DJ's rather than fetishistic audiophiles. I think that, on a less epochal scale, asking if records will completely go away is a little like asking if paper books will completely go away...
