Because Dell is not one person, but it seems you aren't interested in companies that can offer you a decent laptop pretty cheap
I was speccing laptops for my mate and i found one that was on offer at Comet was a lot better spec than any Dells or similar within that price bracket. Dell wanted about 80 quid more for similar spec. without delivery
u can't really get custom built laptops as such, you get base models then it depends on proc/memory- what specifically are you looking for that you can't get?
generally, laptops aren't customisable due to the nature of the them - they all use manufacturer specific parts
