It is the best weapon for its level range, even superior to the Runed Sword and Nightmare Blade. Its value may vary a lot among worlds, especially world types as they are obtained via Warzones which are considerably tougher on Open PvP and Hardcore PvP worlds.
There are no NPCs who buy this sword, so a knight can stand to lose a lot of money by investing in it. For that reason it may be better to settle with Mystic Blade until The Justice Seeker (almost equivalent) becomes available.
However on some older servers the price can often go as low as 4000-8000 gold if not less, making it a very cheap sword that is just as good as the The Justice Seeker and can be gotten 13 levels earlier at a significantly lower price. When prices are this low it makes it one of the best swords for knights in the level 62-100 range to have and a sound investment.