Lineage 2 Adena players dole out their effect over time instead of delivering it all.
They are not terribly expensive, so you should skip the regular CP Potions and stock the Greater CP Potions instead. They can be used repeatedly with only a small delay, so they can significantly impact how long you stay up under fire. They are rather heavy, though, so characters with lower weight capacities are likely to find it difficult to carry these around in bulk. The Healing Potions you can buy from the NPC store are decent for ping if you lack a healer or want some extra insurance, but for Pap you definitely want to obtain Greater Healing Potions, which are drop/spoil only. They spoil fairly easily, but farmers tend to inflate the prices a bit. In any case, GHPs are great, but you're best off using them as a preventative measure. That is, Lineage 2 Adena players dole out their effect over time instead of delivering it all at once like CP Potions do, so you should get a GHP going right before you begin taking damage.