I'd say that's pretty average, although, by the other comments, it looks like maybe not…
I wear a large pair of Columbia Silver Ridge 2 convertible pants. With the supplied nylon belt, they weigh 12.6 oz. TBH, I have been fine with them, despite the weight (that I always figured was good until this thread…) But, they fit me better than any of the other pants I tried on, I love all the "features" that they have (which are really just pockets and the convertible option). They are "light" enough so that they breathe fine on hotter days, and they dry super fast when they get wet. They have lasted me the last 5 years now and while they are dirty looking (they are tan colored) and even has a little melted spot on the bottom of one of the pants legs, they are still holding up quite well and I look forward to using them for at least a few more years.
Saying all of that, I would really love to go the the MB Dynamo wind pants. These are super lightweight (about 2.5 oz) but have absolutely no features (read: pockets), which is why I have not went with them yet. But, John Abela has used a pair of these for something like 1200+ miles and he has great things to say about them…