Hey Nash,
I still haven't done what I was thinking but I think I'll have the x-Line front/rear bumper parts and side skirts installed in 1 or 2 months. To give you an opinion about the prices: Bumper parts + side skirts~= 500 Euros authorized dealer, 2-3 weeks delivery. 400 Euros outside 1 and a half moth delivery. Similarly, chrome window trims are about 125-150 Euros (Price of all 6 pieces). The aluminum roof rail is 850 Euros at authorized dealer and I think the matt black ones are not cheaper than 600. And there will also be additional installation fees.
I won't change my black rails since it'll cost me 850 + my unused black rails. So, the lower x-Line parts and maybe the high gloss shadow-line trim.
Hope that'll help