You can generate the template directly from PSS. In File Center > Schedule a Job, go to Import Cost Overrides and a template is made available for you.
All that is required is the SKU and Cost. The SKUs will need to be in the PSS format and the prices entered as a decimal value without the $ sign. An export of Cost Overrides will give you a receipt of all the SKU's that have had costs assigned to them. Please remove any templates notes prior to uploading.