Ceriatone are selling high quality completed Champs for £170 and making profit! £700's a rip
Whoa! Now hold on there bald eagle.
The cheapest complete amp (i.e. valves, head cabinet etc) is USD 403, then don't forget to add shipping at USD 198 for 20kg (adding USD10 for insurance) giving a total of about USD 600. That's £353 at today's rates.
Then add VAT at 17.5%, plus duty (both on the whole price inc shipping). Call it 20% altogether plus the shippers admin fee, say £75 roughly, giving total of £428.
That's for a head not a combo. With no worthwhile warranty.
If I was doing a champ build, as a combo, with a UK sourced cabinet, 12 months warranty and a decent speaker, you'd be looking at £450-500 if I used Ceriatone parts and vinyl, not tweed. In Tweed with US sourced parts, that'd be over £500.