Mine vs sparring pit
The topic of mine returns has come up a few times in chat so thought I'd open a discussion into the mine vs sparring pit.
Each level of the mine costs 500 gems for a total of 1500 and takes 100 days to return a profit. The general feeling seems to be that those in the game for the long haul should choose this option first but I am not so sure.
It also costs 1500 gems to unlock all base level sparring pit slots. Base level slots return 2k xp/hr for a total of 10k xp/hour if all 5 are unlocked.
That equates up to 240k xp/day from the sparring pit (assuming your upgrading champ levels each time they are eligible to upgrade).
Over the 100 days of a mine paying itself off, the sparring pit would generate up to 24 million extra xp points that I can use to upgrade food.
I've heard of people getting up to 7k per run (4 energy per run) on some instances which if my math isn't completely messed up means a fully unlocked sparring pit first could save almost 14,000 energy (more if you can't manage 7k xp/run).
Am I thinking this through correctly or have I missed something. Interested in all opinions.