@bilirubin
11400f and b560 msi pro vdh wifi would cost around £240 that would be a decent upgrade.
How much you got to spend ?
Not really set myself a budget Mick however I am trying to keep it sensible as I don't think Train Simulator warrants all the top end specs and I have no intention of getting into the more modern games. The £240.00 you mention is doable as is the recommendation that Jigger made above.