Cheaper To Buy Avoiding Scene Tax

We’ve still got my mums one , we just cannot part with it after she passed away last summer
Ours is very low mileage, probably not desirable but a lovely clean car all the same

Define cheap please?

That was my target budget for years running"bangernomic" cars, but it's definitely a challenge to get anything I would happily roll around in for that at the moment.

My current daily is an 03 Multipla, that I bought for exactly £500 in 2016.

I get that feeling reading nearly every post on here nowadays tbh!

Aging is weird.

Just bought this clean little 1.8 diesel fiesta van £600

I bought a cheap 2006 Ford C-Max for daily duties and to me, it still presents as a fairly modern car even though it's now 17 years old.

A 17 year old Ford, when I started driving, would have been a mid 70s Cortina, which would have seemed old to me, at the time. 

Ageing is weird.

I've also noticed a sharp decline recently in the number of first generation C-Max models on the road, compared to even a year ago. They all just seem to vanish overnight. I remember the same happening with Sierras and Cavaliers.

Aging is weird, definitely. But there's also an element of 'perfection' now. Cars aren't necessarily getting better, but they're easier to live with for longer and lasting better, which is why they're now being packed with gadgets to appeal to Joneses types. My daily's a mk5 GTI. It's eighteen years old and it still feels modern, because it's got decent aircon and a stereo that I can fill with music from an SD card. If you could buy a new Golf GTI today, it'd probably still have decent aircon and the SD card would be gone because of enshittification and you probably need an app to listen to music. But I digress. We're now living in a period where the car has been perfected, and it feels weird because there hasn't been a twenty year period before now where the then twenty year old product was as good as the current one...

I think "old" cars were more noticeable then because the differences in car design between the mid 70s and early 90s were quite significant. Going from chrome bumpers, vinyl roofs, coke bottle curves etc to the smooth, flush fitted all in one designs was a major step. Just put a Mk3 Cortina next to a Mk1 Mondeo to see what I mean. 
On the other hand, the car design trends of the noughties are not so dissimilar to those today, the only major change in that period is the SUV-ification of everything, weird shaped LED headlights and the near disappearance of the saloon and estate.