I actually dont run so much. rl is busy. but i'm on my third mythic armor, the first one i sold for 2m, the second one for 1.5.
800 coins arent too much if u consider that m5 gives u 9-40 tokens per run.
i guess i need around 1-2 weeks per armor. if you add the gold loot, legendary drops and the gold elite runner chests its quite a bit of money. + there is a chance of looting a scale, an egg, an armor or even a shard.
i guess thats just my opinion.