So in fact there are no jewels that give archers a big boost for skill dmg and skill crit dmg/ chance that are worth high prices (for not top players). M. Skill, p.atk, m.atk and other stats can be boosted well for a small amount of adena. And yes I know, well geared Yul are OP atm. But looks like jewels are not that big thing a Yul need first.
Epic bos jewels = almost no effect for p. Skill, some have high price...
Angel jewels = +6 and more give a bit for p. Skill.
God accessories = nice effects but expensive like hell.