Hi Keith,
I assume your a guitarist and your passion is collecting. Out of interest what would a quality vintage guitar sell for?
james
To call me a guitarist would be a stretch

Just another of my part time hobbies.
But I don't really consider myself a collector, in the sense of what one would consider in today's world. I just buy them and play them.
But, if I may I think I see where you are going here, and you are absolutely correct. For example, a 1968 Fender telecaster, for example could fetch $30,000 to $40,000 in the right condition. Yep, that's your five 28BSSTs right there

So, there really is no difference between the two, buying a $40,000 guitar and buying 5 amps at $40,000.
However, I also would never even consider a $40,000 guitar...or even a $10,000 guitar. But that's just me. There are people out there that just must have the $40,000 Telecaster...because it's 'Vintage'. But me, I'm just happy to buy the $1,500 new Telecaster (which I may buy today

.)
One note though, vintage guitars are now like art. The people paying $40,000 for a vintage Telecaster or even $200,000 for a 1959 Les Paul

are not playing them. These are going into temperature controlled rooms or kept locked away intheir cases (for the most part) as trophies and conversation pieces. Nothing wrong with that, but that's the equivalent of buying the 5 28B SST and keeping them in the boxes, locked away and hoping they go up in value in the future.
The vintage guitar market has turned to an 'investment decision' as opposed to a 'consumption decision'. Not many people buying a $40,000 or $200,000 guitar would do so if they though they wouldn't make money off it in the future as it appreciates.
I view my guitars/amps and audio gear as stuff I will use every day.
Keith