£450 for that Vanquish seems excellent value.
Check out WMB March 2012 page 22 for a review of the Carrera Vulcan MTB at £360 and just weep.
I have an old (>10 yr) Carrera steel frame built as a winter hardtail and it just quietly does its job.
I have a few Carrera Hellcats (by Merida) built in different flavours and love them. Simple massive single pivot that I cannot wear out and standard fittings for BB, headset, seatpost etc.
Carrera are tarred with the H*******s reputation, but once you look underneath that and do your own build/maintenance they are brilliant value.
I have other more expensive bikes, but fear breaking them and consequently ride them less.
PaulD