Volk, for that money the Tamron 18-200 is excellent - currently available here for just over 200 euros. It's light, has a great range, but I sometimes miss stabilization, especially at 200 mm. I'm thinking about buying the Tamron 18-270, not so much for the extra millimeters but for the stabilization. Anyway, 18 mm is too narrow angle, especially for mountains, so I always carry a wide-angle too.
Medo, this lens as the only one for hills I certainly wouldn't recommend.

28 mm is way too narrow on most modern DSLRs (with crop factor 1.5 or 1.6), where due to smaller sensor 28 becomes 38 mm.
Pikec, you won't miss with either one or the other.
