What is the correct total cost calculated for a homeowner’s project if they plan to do the work themselves and only incur supply costs?

In this scenario, the total cost for the homeowner's project is determined solely by the supply costs incurred, as they are completing the work themselves. This distinction is important because it eliminates labor costs from the equation, focusing exclusively on the materials required for the project.

If the homeowner has accurately assessed their supply costs and calculated them to amount to 20,000, then this figure reflects the total expenditure related to the materials they need for their project.

The other options indicate higher amounts, which would suggest that there were additional costs involved, such as labor, which is not applicable in the case of a DIY project where the homeowner is not hiring outside help. Therefore, the correct total cost of 20,000 captures the essence of a self-managed endeavor focused on material purchases only.