If you have access to System options in Elite, you will be able to enable Cost+Plus Billing in POS.
1. Click the left Hamburger menu icon.
2. Click on the System menu.
3. Open the System options module.
4. Go to the POS 2 tab.
5. Switch on the "Enable Cost+Plus Billing in POS for selected Customers" toggle. When it’s on, the round part will move to the right and change color. 
6. Select one of the following options from the "Cost+Plus Billing (Cost+Plus Matrix) settings:
A. Cost+Plus Billing using Weighted Moving Average Cost OR
B. Cost+Plus Billing using Last Cost OR
C. Cost+Plus Billing using Standard Cost.
7. Click on the Save button in the navigation bar:
8. A system message will appear:
Save System Options
System options are applicable to all users.
Do you wish to continue saving these changes?
9. Click on Yes.
10. A system message will appear:
Options Save successful.
11. Click on OK.
NOTE: For the change to take effect, close the Point of Sale application on ALL the computers, and open Point of Sale again.