Boxing champion Floyd Mayweather has just offered UFC champion Conor McGregor $15 Million USD for a crossover fight. This comes in response to McGregor’s challenge proposal back in September 2015. The deal would involve $15M USD in cash as well as a cut of the pay-per-view earnings. This could mean yet another massive payday for the two outspoken fighters. Mayweather is currently retired with a clean 49-0 record and hasn’t fought in the ring since 2015. Everybody is now eagerly awaiting McGregor’s response.