Look on the rear of the blade, by the crosspiece you will see the Crown/W emblem (Kiaser Wilhelm) plus a two digitnumber (year)...that will date the bayonet.
Solingen is the place the bayonet was made
Luneschloss is the maker's name.
Rare? Not sure.
But $360 sounds OK to me. Retail on these in the UK is around £300-350 (x 1.5 for US$) for a good original condition knife with scabbard
Always good to do a quick search on EGay to see what is out there and the sort of condition/price.
Search "German sawback" and you'll find several 98/05 bayonets ranging from around $700 downwards right now......