User blog comment:Gracchus Mccarthe/How to cheat with Black Strongboxes. MWAHAHAHAHA!!!/@comment-25926644-20150724041254/@comment-25461088-20150803013255

I did a bit of math. 400,000 XP is equal to $8,000,000. Assuming I get on average $1,000,000 every two Nightmare games I play, that results in 16 games to get that key. Since I get about 16,000 XP every Nightmare game, that results in me getting 256,000 XP, and considering I just levelled up, I need about 500,000 XP to level up again. Perfect!