The expected value of the crystal chest is 24,625.96.
If you drop all the useless loot:
The expected value of the crystal chest is 24,285.51.
The expected profit is: 1,981.51.
Expected inventory slots per key: 2.53.
Steam rc w. water tali / no pouch. Profit per inv: -193.5.
Lava rc w. earth tali / no pouch. Profit per inv: -1,667.5.
-20,898 gp - 28,080 xp -0.74 gp per xp.
-180,090 gp - 29,484 xp -6.11 gp per xp.
180.9k gold more for 1404 less xp. == pay 129gp/xp for 5% higher xp rates