@Tenecia.Seeley if this is a Purchase part setup as Weighted Average and Cost Per Part, then the system will automatically update the unit cost every time there is a new PO Line receipt. It will evaluate the cost of the already existing stock and calculate the new unit cost considering the PO Line price.

Hello @Tenecia.Seeley 

You can change unit cost on inventory part window. Find your part and go to Costs tab. Click RMB and Modify Level Cost Details

Write the cost on New Cost column. This will create inventory value increase/inventory value decrease transactions automatically.

Hope this helps

@gumabs that option is greyed out for me?  Do you know how I can open that open to allow me to update it?

Hello @Tenecia.Seeley 

This could be a permission issue, can you check your permission set?