We need to choose our quests carefully according to our goals during the "November - Zombie Invasion" event. Because the rewards of some quests may not be profitable depending to our goals.
As an example: take "Resurrect the Dead" quest from Shiko the Paladin. It requires 3 coins and one amulet of resurrection (costs 5 silver) to complete, and gives premium elixirs and 50 silver as reward. If your goal is save money in this event, this quest is profitable. But if you want to collect mithril palms as much as you can, it's not. Because if you complete the quest, you'll at 3 mithril palms loss since you could burn them at necrus sphere.
And also "Cross Palm with Gold" quest from Nadilarie. (Its not available yet so I searched in forums, if I didnt get it wrong)It requires 3 coins and gives 2 palms and a zombie gift. If you want to collect mithril palms, its not profitable because you could get 3 palms when burning those coins.
If you want to save money, I recommend you to don't waste your time doing "Liche Curse Amulet" quest from Gizedor, because it costs the same as the reward. It requires two gifts that cost 25 silver each, and gives 50 silver, mithril palms and a chance of liche coins as reward. But if you want to collect more mithril palms, you can do that either.
If you wanna collect Mithril Palms, you should do Burial Rites and Feed for Drowned Girl's Pet for now. New quests will be available soon.
If you wanna collect as much gold as you can, you should do Burial Rites and Resurrect the Dead quests for now. New quests will be available soon.
Besides these, don't forget to visit urchi daily to get extra mithril palms. It's quite forgettable