I only have one part number with that number. I will call tech support. Thank you

I am trying to change the cost price on an inventory part and it keeps telling me that "This part number must have a unique part number and description." I have no idea what is causing this. I do not have this issue with my other parts that are similar. I have been updating this part for a long time...

Thank you so much for the explanations. Makes better sense now.

I am trying to figure out my percentage for my overhead markup. I watched the video, but not sure I am understanding clearly how to get my % amount. Can someone further explain to me so I can get an accurate report.
Thanks