Swiss 1889 pattern bayonet, could be used with either the 7.5mm Schmidt-Rubin (1889 rifle) or the K11 rifles.
Looks like it may have been manufactured at Waffenfabrik Neuhausen, although the markings are worn down. Does it have matching serial numbers on both the bayonet and scabbard?
As for value, with bayonets condition is everything. The finish looks decent, although the blade is stained (possible that it could be lightly cleaned to remove some of the staining), grip scales are in very good to excellent shape. A matching scabbard and bayonet s/n would be preferable... It may be worth $150, if matching to the right person. It may be worth more if someone really wants it - but it's a pretty bog standard Swiss bayonet, unless there is some sort of interesting markings, etc.