How to input task fees not based on hourly rate, invisible to team members

Hi,

Our company and espacially the department I'm managing, is offering services based on hourly rates, which is well managed by Wrike to make that information only visible to people in the team we want to, and we also offer services based fixed price.  So my problem is that I'm not seeing and easy way to get that information in the task so it is invisible to others as is the financial info for the Actual cots, fees, planned cast and fees are right now in Wrike.

I guess I could take that amount for the task, lets say 3000$, and make a custom hourly rate to arrive to that amount, but since my employee will continuously work on this, the hourly rate is always changing...

I tried to create a custom field, Task Fee let's say, and to get my profitability, I created a calculated value to get my employee's cost to that Task fee.  The problem is that the people in the project can see that information and I don't want that...  They could learn what is the salary of others and this will bring a serie of problems...

Do you have anything to help me here?

Thanks !