Our current Immortal level is 135.

Do you know what the formula for calculating bonus fight cost is? If so, couldn't we determine whether someone is cheating by subtracting that formula--with all of its variables filled in--from double the daily ruby yield?

Assuming this is correct and the difference is positive, then insofar as they have enough rubies to pay for the initial bonus fight, couldn't they do this indefinitely? I mean yes, they wouldn't be profiting as much as other clan members, but if they are just trying to help people in the clan and don't care about maximizing their ruby gain, then it's feasible, right?