In the last 2 years, I guess since just before the pandemic, prices on vintage or desirable instruments have rocketed up. I agree overall they haven't gone up much more than inflation but something has changed again.
No the amount of disposable income has plummeted among the younger demographic, but it is not them that are buying vintage fenders, it is much older people who are doing it, and that disposable income has increased. Young are doing what they always were. They are buying 5-10 year old basses like they always have, just that a 10 year old bass is now 2010, whereas a 10 year old bass when I started playing was a 68-70s.
When I first started playing the one thing everyone would say is not to buy and old fender (ie, 70s) because they were terrible. They weren't, some were ok, some were bad some were great.
At the moment and over the pandemic, a lot of people have got a lot better off, although the overal amount of money people earn hasn't moved at all, the top has really accelerated away from the bottom, the gap between the top 10% and the bottom 10% grew a lot.