In GanttPRO, you can also track the actual amount of money spent on a certain task. That way, you will not only see the estimation values but also precise spendings that account for other aspects. Check here how actual costs are calculated.
To enable this option, switch on Actual cost field in Standard fields in the project grid.
Note that any resource in your account can be utilized in different projects and have different cost values and types in each of them.