use an expert/superior salvage kit. there is no dmg mod on the sword so it has no value on its own.
Salvaging can either get you the preffix, suffix (in this case sundering and swordmanship mods) or materials.
The prices of mods should you salvage one can be found in the baseline weapon mod prices sticky at the top of this forum
pc Sundering Broadsword of Swordsmanship
Peachie