A Yul Sagittarius? Nice. Don't see too many of those. Most are Ghost Sentinels or Moonlight Sentinels.
Generally speaking, the next level up from the Rare Accessory Pack Boss jewels -- but before Dragon and God jewels -- is the regular Boss jewels augmented with Silenite which give a minor boost. After that it's Ring of Authority, +8 or higher Angel jewelry and the Rulers Authority Ring. Some are better than the rare pack jewels, but maybe not for the prices that people are asking. I mean I wouldn't pay 20-30B for a Rulers Ring of Authority. I'd keep using the Earth Wyrm and Tauti from the pack, save up and take my chances on crafting a Sayha ring.
The good thing about archers is every little bit helps and there are lots of ways to make them deadly. If you've neglected jewelry, what about artifacts, la vie en rose jewels, cloak, bracelets, circlet and agathions? What about your skills -- have you enchanted them?