Carbon fibre also has the advantage of being more hands-friendly in very low temperatures. If your hands ever remained "glued" to a very cold aluminium tripod then CF would help.
That said: if you bring your tripod with your for many hours on the mountains, go for CF.
If you use your tripod for a normal let's say 2-hours photography sessions then I'd suggest to save the money for something else.
Don't forget tripods are something which are at risk of being forgotten (think tube, train, restaurant, it's a bit like an umbrella) or stolen (car trunk) more often than a camera. For instance one would not leave his camera in his car trunk, but it is more common among photographers to have a tripod in their camera.
Aluminium is good stuff. Wood would also be good in very cold climate and I would consider it an alternative.
For landscape I would advice a three-way head rather than a ball-head, but that goes down to personal preference a lot, so YMMV.
Look for features like rubber/spike under legs to be changed easily or instantly (so that you can adapt to mud or rock).