Adding cost price rules in receipts for employees and hiring

Cost price/purchase/hire separated from the table sales/invoice lines

Keeping it in separate tables allows you to deviate in sales from your purchasing

3 possible situations for which cost prices can be registered
Own personnel material - cost price of operation (cost man + machine/vehicle)
Hire material - cost price own employee + purchase invoice of material
Hirer - register cost price of hiring + material in table to check purchase invoice and in future add self-billing

Working with cost price and purchase of materials we can show more business results/reports in TimeKing in the future. Just think when this can be simply registered and put in a separate table