If you like to ask how much could cost for case to some professional center with "big" 3D Printers , could be useful.
I'm waiting a quote from
http://www.solido3d.it/ , anyway they could print inside a cilinder of 400mm of diameter , that is enough for a 14inch notebook (31,4 cm x 24,5 cm) not for a 15 inch.
There are other solutions like:
Vacuum casting ( smooth looking but expensive - around 450 euro only for the notebook case) or
thermo forming (cheaper than Vacoum, less smooth looking , more complex assembling).
Anyway I will update you about the quote for 3D print , if you like search around you for have other quotations.