Sometimes people will ask me for recommendations on computers and home systems. I've always said that they should spend at least 50% of the total budget on the display, as display tech tends to last a lot longer than anything else and display quality/size is often the biggest determinant of user happiness (folders excluded).
Novice buyers are usually surprised by this advice, but I think it's been appropriate for most users. I wonder, though, with the advent of pretty good low-cost LCD's if I should revise this number downwards a bit.
Do you all have a rule of thumb about this sort of thing?