Interesting you mention BKPs in this, Bob
I was chatting with Tim once about pickup design and history and PAFs in particular. The topic of paying vast sums for original pafs came up and Tim said that the originals, and all pickups back then, were wound one coil at a time by (often) immigrant labour that had (always) only rudimentary winding training, and all the coils thrown in a bucket, mixed together. The winders started untrained but eventually became very good at what they did, but not consistent from one winder to the next - occasionally the pickups that resulted from the random combinations of these randomised coils were awesome, but mostly they were rubbish, and he's done a lot of research to find out what made the awesome ones awesome. Ergo you get a better pickup now than you do then. Maybe betters the wrong word, actually, but certainly more of the pickups made by tim and guys like him are better now than then.
Upshot, IMO (not tims, he didnt say this part) people that pay thousands for original humbuckers are misty eyed fools that have more concern for image than sound.
Vintage guitars are clearly a marketing device, but only because theres a market for them (Bob outlined that market - the, to phrase it as charitably as I can, nostalgic-and-not-rich), but theres also absolutely nothing about a vintage that makes it sound better.
Someone else I know thats remembers the early days of electric guitar is quite scornfull of the instruments from back then, saying "For every good strat you found in the 60s there were 10 more that sounded like a car being chopped up with a breadknife".
Plus the main innovation of Leo fender, for which he is to be applauded, was designing a guitar that was easily built by an assembly line. Back in the day they were made from whatever wood was to hand, very often with 3 piece bodies, the woods sometimes differed from piece to piece in the same guitar.
Thats one of the reasons that guys that played them then played one, maybe two, and they were all worn to hell and back - look at SRVs frankenstien N#1, rory gallachers strat, jeff beck et al - they obviously like strats in a general sense, but they found one in particular that happened to do it for them and played the $%&# out of that particular guitar. You'd be an idiot to think that they hadnt tried out hundreds more and rejected them. People often take these players going for them as being testaments to strats, and in a sweeping way, on the overall design and feel of the guitar it is, but its also a testament to how hard it was to find a good one back in the 'vintage' era.
I find it quite pleasantly ironic that one of the reasons people lust over old strats (old players they like played them) with a little closer inspection provides a reason to not think that theres anything generally special about them :)