By the 90's the current mindset was firmly established and we were paying a premium for mtbs as they were , relatively , the newer thing . I was thinking further back than that ,{50s , 60s and 70s} when the choices were more limited by the materials available and local manufacturing was still financially viable and people expected things to last longer . I didn't say that , apologies . That said £340 for a Vitus of that spec is a great deal , kudos .
Edit : I just checked and Vitus are listing it at £600 , still a good deal .
Chainreaction have it at 400:
https://www.chainreactioncycles.com/p/vitus-nucleus-27-vr-mountain-bike-blue
Probably fair to say that most bikes in the earlier eras were more expensive in terms of proportion of salary. And that if there were cheap and nasty ones, they probably haven't survived. In the late 1800s, bikes were largely hand built and a luxury for the well off. I'm not sure we want to return to those days either.