I think a lot of guys fall into the old trap that "they doln't build them like they useta."
Well, that's true, they don't and we should all be thankful for that fact.
Do any of you really believe that each new model is not a safer, better designed and engineered car than the one it replaced? And when I talk about design, I don't mean how it looks, I'm referring to how it was designed to go together.
Early Commodores, and by that I mean everything prior to VT, were weak structurally, almost totally lacking in the sort of primary and secondary safety that we take for granted these days. If a VE can just manage five stars for safety, how many do you think a VB to VL would score? Probably two, if it was lucky.
You can spend $5000 buying and building up a pretty decent VB, but all you really have is a nice VB - thirty one years old, live rear axle, ancient engine and transmission, really shithouse interior materials and dodgy electricals. Cheap to maintain and repair? Yep, sure. Safe? Nope, not really. And unless you modify the engine or replace it with something more modern, you have to use premium unleaded with additive every tankful. What a pain in the arse.
For the same money you can buy a half reasonable, high mileage VT, with mayber 200,000 on the clock that is still a far stronger, safer and better handling car than the $5000 VB. It mightn't look like much, but it's a great start and parts are now much easier to get than VB parts.
There is definitely a place for modified earlies, always will be, but they are like old traditional Holdens - getting hard to find, difficult to source some critical parts and requiring fuel that is no longer available.
Later models are now so cheap and offer so much more for the money. I think that has to be a major reason for the situation raised by the OP.