Please don't pay for upgrades! Earn them
Given P2F FO's are bad enough at least you have a captain there if the
hits the fan.
If things go wrong & you have a P2C*& P2F FO you really have nobody to fall back on to make the right decision.
(*P2C - pay to command)
I don't like this idea or rishworth one bit, shame on them for promoting this dangerous concept