A great old thread, Jon!
Having been in the business in both eras, it becomes a most interesting question. Most pieces of gear and software were in our store in the '70's. I own(ed) many of the classic Quad pieces and lots of domestic software.
1976 portal:
1 - Marantz 4400 - I still own a Marantz Quad that I bought back in the day, replete with full-logic SQ module, remote, and wood case. I'd love to trade it for a 4400, although I'll put my B&K 7.1 separates and it's array of vintage "black boxes" (SQ, QS, CD-4, pre-preamp, dbx II, Quad scope, Zektor HDS 4.1, and Russound QT-1) against ANY Quad piece(s) including this one, performance wise.
Still, a most cool and very collectable piece, and WAY BETTER LOOKING than my modern two flat black B&K amps, and the preamp with a 10" x 2" blue display for input/mode. No sex appeal at all! I recall the 4400 being a $1400 list price, which would be about $4k in today's dollars. Still, I never liked the "uneven" rectangular buttons and the scope display is teeny. With all due respect to Sansui lovers, the 4400 is the best and coolest Quad receiver.
2 - Pioneer SD-1100 Oscilloscope/test tone generator. A piece I may still own before I die. At the height of Quad, we had this piece displayed on the console where our audio board was. We usually demoed CD-4 through 4 Altec Voice of the Theater horns! Quad on steroids! A couple years later, I bought a Technics/Panasonic SH-3433 Quad scope for 1/4 the cost. The Pioneer is way cooler. Original list price: $600. That would be nearly $2k in today's $$.
3- Crown International CX-844 10 1/2" reel 3 3/4, 7 1/2 and 15 ips deck. The REAL deal and a piece I still hope to own someday. There is a photo of its' little brother, CX-744 in this QQ thread:
https://www.quadraphonicquad.com/forums/showthread.php?8643-Crown-International-Quad-Reel-Decks
Crown ceased making reel decks in the mid-70's, because they were very expensive. They continued to make amps/preamps. It was $3k in '74, the same price as many cars!! It would be about $10k in today's $$.
CX-844 picture, with grid of available 70's Quad reel decks, from Reel2ReelTexas:
http://reel2reeltexas.com/vinAd66RecB3.jpg
This company is not the same as Crown Japan, which made low-cost amps. This Crown was in Elkhart, IN.
2004 portal:
Although there are many modern pieces that would outperform my current main system, there is very little gear that I'd love to own from the modern era. Just as I'd love to have J Lo's assets, I'm satisfied with mine. I'm content with most of the gear I currently own, nearly all of which was purchased either in the new millennium or in the old Quad days.
1- A JVC HD D-VHS deck.
2- 50 copies of the DVD-A of Fleetwood Mac Rumours to sell on E-Bay.
3- 5.1 SACD Bach: Four Great Toccatas - (Old Ernest) E. Power Biggs. Again, many copies as an investment.
I do own A COPY of both software titles.