WorkGuru allows you to quote your tasks at two rates. Which one works best is determined by your quoting and invoicing workflow.
Note: You can set the default rate on your quotes by the Default Quoting Rate Method dropdown in Administration -> Settings -> General
Task Rates
Tasks rates allow you to bill your labour based on what work is being done at a fixed hourly rate, regardless of which staff member completes the work. This is the default setting in WorkGuru. 
When adding a task the quote when set to task rates, the forecast cost and the quoted rate is set by the task setup. In this example the forecast cost for an hour is $35 and the quoted rate will be $75.
When invoicing task rates on the project, the actual cost is the user's individual hourly rate from their timesheet, and the invoiced rate will be the quoted task rate. In this example, actual cost for an hour is $80 and the invoiced rate will be $75.
Staff Rates
Staff rates allow you to quote the labour based on who is forecast to do the work at the individual staff members cost and sell rates. You can select the Quote by Staff Rates? checkbox or set the default method in the settings.
When staff rates are enabled, the sell price will disappear as it is now determined by which staff are assigned to the task and their forecast allocation of hours. To quote staff rates, after adding the relevant task, you need to expand the task and allocate staff members and specify the time allocated.
The quoted forecast value will be the hours multiplied by the allocated staff members cost and billable rate. When quoting more than one staff member on the task, the forecast cost and rate are the combined hours x rates.
Note: When the project is created from the quote, you can re-assign the allocated as required to track the actuals correctly.