Buy orange chests to level up gray to orange levels: only buy red resources for the red levels
Beyond That
Past 200 artifact levels, be warned that the next emerald coin threshold is not easy to reach: you need 10k energy + 375 artifact chests (325 with 5k emeralds)!
On top of that I recommend to save your artifact chest keys for Weaving Patterns instead, so it may be better to not spend those resources and leave it at that
4000Level up any Hero's Artifact 10 times200Level up any Hero's Artifact 20 times200Level up any Hero's Artifact 30 times200Level up any Hero's Artifact 40 times200Level up any Hero's Artifact 50 times200Level up any Hero's Artifact 60 times200Level up any Hero's Artifact 70 times200Level up any Hero's Artifact 80 times200Level up any Hero's Artifact 90 times200Level up any Hero's Artifact 100 times200Level up any Hero's Artifact 110 times200Level up any Hero's Artifact 120 times200Level up any Hero's Artifact 130 times200Level up any Hero's Artifact 140 times200Level up any Hero's Artifact 150 times200Level up any Hero's Artifact 160 times200Level up any Hero's Artifact 170 times200Level up any Hero's Artifact 180 times200Level up any Hero's Artifact 190 times200Level up any Hero's Artifact 200 times200[+]
The quests and shop have been specifically datamined for June 2, but the quest rewards come from May 2. It is speculated this event will be the same because they share the same quest structure.