...Dave, not trying to pick a fight, as I'm headed out the door to see 'Birdman', but I had to reply to your post...
"It appeals to many demographics and above all, everyone can relate to some aspect of it at a personal level."
...as does music - I'd argue even more so...
"From owning a car, working on it, filling it up at certain stations."
...from seeing a band, buying your first guitar, playing in a garage band, working in radio...
"Personal or family memories of relationships with certain brands or products."
...that song that got you to buy a guitar; that song that reminds you of a high school sweetheart; Elvis, Beatlemania, Woodstock; John Lennon's assassination...
"Or as simple as the bold graphics or marketing associated with some of the products."
...the clean lines of a vintage Martin guitar...Gibson Les Paul...a rare Flying V...etc...etc...
...I don't see any real difference...the prices are driven by the same emotional attachments/fetishes...speculators are drawn in to ride the elevator while it's moving, and leap off, as soon as it stops...
...while there are a few folks on Oldgas whose wallets/disposable income strain credulity, the fact remains that 70% of Americans make 50K a year, or less...how many of them can afford $2000 signs? or $200 signs? How many worthwhile $200 signs are even out there, priced for the beginning buyer?...