It is not a K11 it is a Gewehr 1911. It was made in 1916.
Value wise I would say in the 400-600$ range provided it is all matching. Not nearly as common as the K31, but that being said they aren't as desired as the K31. Personally it is my favourite Swiss rifle variant (out of the ones I have handled, only a couple small rare variations I haven't), but that 300m minimum sight setting turns a fair bit of people off.
Issues with it from a quick glance are obviously the finish is worn and it is missing the little accessories (sling and muzzle cap). If it isn't matching numbers that is also a issue.