Cool, thanks. I've never actually played one before.
I can't get exact numbers until I know what the quest rewards are, but I'm thinking we can blow about 1,500 Keys on shuffles and still get 5 Artifacts for a fully evolved Owl.
Anyone else have a good idea?
For some reason, I thought you came back in time for the May event, when we last had this system.
I only just hit 40 keys with quest 72, so your numbers would need to be adjusted slightly downward, though maybe only enough to lose opening one box.
Because of today's good prize, the Goblin Gift Shop, I blew all the keys I had saved up, so now I am at zero and can roughly calculate the remainder of the event for me. Right now, including the artifacts from the bonus gauge, I am at a level 7 Owl, and almost done with the current in-between grand prize, so three dots and five more grand prizes to get three more artifacts. With 23 more days of 40+ keys and 22 more days of 25 free keys, plus the ground drops.
If you are going for the grand prizes only, 16 boxes means 16 points toward the grand prize, plus either two or three of those give extra points, plus the 2X also doubles the point, so at least one extra there. This means if you open all 16 boxes, you are guaranteed enough points for one grand prize, plus maybe a point or two extra towards the next prize. That is 400 keys per set of postal boxes, then the free shuffle, then repeat if the daily is worth it.
For me, 880+ more keys from quests, 550 from the daily free keys, plus average of 20 keys per day in drops for another 460, including today. That looks like 4 more grand prizes guaranteed and at least halfway to the final artifact. Depending on exact value of the final 23 quests, plus how much I can actually collect in drops, plus how many boxes contain extra points, I might just barely get the 9th artifact from the event. But more likely I will end the same as the past several events, just short of the 9th artifact.