Thats exactly right. We as a main dealer struggle to sell used 1-3 year old imports for any more than a grand less than equivilent UK price as customers know money was saved up front and so don't expect to pay the same. The general rule of thumb is if you sell within three years, you'll lose what you saved so it'll cost the same in the long run.
Incidently, I spoke to a dealer today who has a white GTI mkV Import for sale. This car has leather, sunroof etc but aircon, NO CLIMATE CONTROL. If you are importing, check this kind of thing because that is going to kill it's resale value. People can live without factory options but will expect standard UK spec.