Only Users with the appropriate User get access to the Budget module in farmerswife:
- Can See Budgets
- Can Edit Budgets
Combined with Project, you can control that a User can only edit Budgets on those Projects where they have permission.
Task Users can have the Can See Budgets permission enabled. They are then allowed to see which Details and Quantities are in the Budgets, but not which Rates or Totals they have.
A user needs to have the Can Edit Budgets enabled in order to do any change in the Budget, including the use of the Scheduling Mode or attaching Actuals.