I can buy bikes that look like that around this area and south for around 100-300 almost every day on craigs. Where you live is very dependent on what the price is, I live in Harley, big road cruiser country. They look at those things and practically give them away. Hell, I bought 2 ALMOST complete CB 450's a couple of years ago for 400 bucks. My 360 I got for $50 bucks to get it out of someones way. That guy also had an XS650 that he sold later for around 200 and it was a complete RUNNING bike.
Hell in all honesty I just bought a project bike off my buddy because he got tired of it. 74 CB550SS that he's sorta more or less butchered up to try to make a cafe. $600 got me a low miles bike that runs and needs FINISHED. I'll give him credit, it was mostly ugly when he got it, its not BAD now. Point is it runs, I can get on it and blast around the block pissing the neighbors off if I want. Oh yeah, and I also got his NICE Miller MIG welder in the deal.
Just because its OLD doesn't mean its a good project. If that was say a BSA or a 69 cb750 I'd be about it. Paying more for something because someone says the price has gone up because of a FAD or IDEA is silly, most times you see things like this SIT for months because the guy got way too much money into what they have done and NO ONE will INSURE IT for that cost. They are still cheap throw away bikes, just like they were in the 70's, meant for cheap transportation and/or to learn how to ride. That's why most of them have low miles because they got ridden for a season, put away and replaced with something bigger. Either that or the girlfriend didn't like riding and parked it.
Now, I'm not gonna lie and say I wouldn't buy this bike. It would have to be dirt cheap and I would consider it a parts bike. Something like that doesn't scare me but when you already have 3 other RUNNING RIDING motorcycles, what's the harm in a 4th parts bike. It will sit right next to my other parts bike. ;D