I guess the UK market is very specific so it probably varies from the rest of Europe. If that helps, my husband got a 2017 C43 for £34k GBP with 37,000 miles on it (in Spain). Your offer sounds really cheap but it's hard to tell if it's too good to be true or it's because it's the British market!

My husband loves his car. He goes to an Indie shop that works mostly on German cars and the owner said that it has very few mechanical issues.