websites do now ask for what extra's are fitted, so i have to disagree with you on this one, and also having recently sold an 05 high spec GTi for £17500, whereas normal condition ones sell for a few grand less. hense why vw resale prices with options vary due to ammount of options on the car. You have to be very silly to chop your GTi for £14k only for the dealer to resale on for £19k because its loaded with extra bits. So extras DO count but dealers wont admit that. More £ in their pocket.
What web site are those then, i'll tell you which ones, the ones you as a consumer have to pay for.
Take it from someone who does this for a living, if you buy a car as a standard car lets say £ 20k, and you put on that car leather £ 1800, dvd nav £ 1800, That now makes the car value £ 23600, if in three years you trade it to a dealer, you car that cost you £3600 more with those options is worth a touch more than the guy who took the standard car.
Options are a choice, its a personal thing, yes selling it privatly it looks more atractive if it has those things, but only to some one looking for them.