I think Coast really is in a different league to the shops you've mentioned. Their clothes aren't 'fashion' clothes, more 'classic' than anything you'll find in Top Shop and personally, I think far better quality and something which you could wear season after season. I agree with Orangesauce1 that a dress new would have probably cost over �100. To be honest if the dress is in immaculate condition, then I would expect to pay at least �40, but then I guess it depends on who's selling it (ie friend or in a jumble sale)