How much do the advisors cost?

They cost less than the value they bring. One can hardly afford not to hire a professional.
Count on CHF 100’000 in retainer deductible from the success fee. The retainer is there to get the commitment from the entrepreneur, that the company is being serious about the sale.
For some, there is only a success fee. The incentive is to get the better price to earn more.
With the target fee of CHF 450/hour, some would start with CHF 275 – 300/hour for the preparatory phase but once there is the money on the table, the rate would double.
For an USD 80 million deal one should count approximately USD 2.5 million fee to pay the work of all advisors, tax experts, contract lawyers etc.