Expenses to intermediaries, including Raiola but surely not exclusively Raiola, expenses assosiated with negotiations (those can't be very high) and then i don't know...
But okay, then let's look at the numbers.
105 million are received, half in cash and half as a receivable, so the it has to be discounted. Also we have to take into account the book value of Pogba, which should be at 4,7 million €. Then there is the bonus of up to 5 million €, which has to be given some kind of value depending on the probability that the bonuses will be activated.
Let's assume that we discount the second installment with 10 % (The club will probably grow it's revenue around this mark as it did last year, even with a lower CL income). This means the amount received in present value is 99.75 million €, subtract his book value and we have a profit of ~ 95 million.
Then there is solidarity subsidies which account for around 3 million, then we are down to ~92 million. This means auxiliary expenses account for 19.4 million €. Even if Raiola gets everything, which i doubt, it's not 25. But it could be around 15 i guess. I am certain United pays him comission as well though, so he will earn a lot from this deal.