The expected value of the crystal chest is 22,366.62.
If you drop all the useless loot:
The expected value of the crystal chest is 22,145.46.
The expected profit is: 1,479.46.
Expected inventory slots per key: 2.53.
Steam rc w. water tali / no pouch. Profit per inv: -396.5.
Lava rc w. earth tali / no pouch. Profit per inv: -1,638.5.
-42,822 gp - 28,080 xp -1.52 gp per xp.
-176,958 gp - 29,484 xp -6 gp per xp.
180.9k gold more for 1404 less xp. == pay 129gp/xp for 5% higher xp rates