Looks like your on Desktop – you should switch on the system option for Inventory ‘units of measure’.
Then define a Bag5 unit for that item which contains 5 pieces.
Now you can buy and sell in single units or Bag5 units and the costing will be correct.
Resolution for 'bulk purchase issue: 'COGS/reordering bulk purchase, individual sale' available: Yes.
The bulk purchase issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the bulk purchase issue yourself by looking for a resolution described in the article. If it is a complex bulk purchase issue or you are unable to solve the issue, you may contact us by clicking here or by using other bulk purchase support options.
For more information about resolving issues related to bulk purchase in Quickbooks/QBO or to get support for the issue 'COGS/reordering bulk purchase, individual sale', click the link below: