......I don't know if I would use asking prices in Walnecks for a benchmark for market trends. A bike is worth for what someone is willing to pay for it, and with Walnecks, you never know what they really sell for. The places where you can see what bikes actually sell for, like Ebay, classic bike auctions, etc, show that original/correct early Z-1 and H-2 prices can be very high. However, I have noticed that minty original and correct CB750's have skyrocketed in value in recent times, and certainly are holding thier own with the Kawasaki's. That said, bikes from both genres can still be found at reasonable prices of one looks patiently for his disired machine within his own regional market....thankfully!
......I know that survior rates for H-2's in my own area were very, very low. H-2's were owned by a very high majority of head-banging (even though that term wasn't around in '72..it fits) very young guys. They rode 'em hard, wrecked them, died on them, and never once put a tool on them. They sat outside year round, were never cleaned, and when they finally grenaded (usually transmission) they were simply discarded......just something left behind in the wake of misspent youth. H-2's were not turned into touring bikes, like many CB750's or Z-1's, they were just pitched. Tranny parts for them were expensive, I know this from painful first hand knowledge!
.....Z-1 survival rates were a lot higher. Nobody threw a Z-1 in the garbage when it was 3-4 years old. They were so expensive new....so many young guys, myself included, lusted after the 'Root Beer 900'. None of us could afford one. Z-1 owners, those who could come up with the 3 grand to buy one, tended to be the older and more mature riders. Fewer Z-1's were sold, but most survived the first critical 5-10 years of ownership. Indeed, some were purchased later in life by young owners, and lead hard lives, but their engineering saw them through much of the abuse.
.....CB750's.......back in the day, they attracted everybody! The young squids, older mature guys, touring people, you name it, you saw anyone on them. There was no set owner genre for a CB. There probobly still isn't to this day. Surival rates, which somewhat dicate prices today, I think, are moderate. Production numbers ensured an adequate supply for many years, for everyone. Factory support kept parts available for those who wanted to keep thier CB on the road. Many, many CB's were wrecked, many were modified to custom or touring spec, but a surprising percentage have made it through to 2007 in relative stock form.......and these are the machines that are commanding higher demand today.
......But, like I said earlier, enthusiests don't have to spend collector prices, for decent Kawis or CB's. There are still gems in all areas, and many are owned by people who have never heard of Walnecks, don't know how to get on Ebay, and just want to sell their bike.... All a guy has to do is start looking, be patient, and have the funds ready to go when the right one pops up.