As a thought, you might want to consider approaching the problem slightly differently. This approach is assuming you are not using an Enterprise resource pool and that you are defining your Designer locally within your schedule…
* Define the Designer as a Work resource so that you can assign them to tasks with hours estimates. You can also then assign the Designer a standard hourly rate.
* If there’s a limit on how many hours a day the Designer can work, look into the Max Units field as this can be used to help constrain the scheduled hours per day.
* Customize a Resource field, using the customizable number or cost fields, depending on if you want to track hours or costs. The customized fields can be used to store the limit you want to compare against. In your example, you mentioned a cost of $5005 or 77 hours.
* Add those customized fields (columns) to a resource sheet type view and enter your limit values for each resource. For the Designer, you’d enter the $5005 and or the 77 hours.
* In the same resource sheet view, add the Cost and Work columns. These represent the at completion values for all the work assigned to the resource in the tasks.
* Then as the project proceeds, you simply need to open the customized resource sheet view and you’ll see the limits side by side with the at completion numbers. You could even get fancy and add flags or colors to the customized fields to help you see where the planned numbers are being exceeded.
Hope that helps, or at least give you another approach to consider