Hi there, AVadmin.

Thank you for visiting the QuickBooks Community. Let me share details on how created items from Time Activity works in QuickBooks Online. Then, ensure you can add the items to an invoice to get the right sale price.

When you enter item details from the time and costs page, the billable value appears as the rate on the Invoice page. Then, the Amount field was calculated by multiplying the duration by the amount entered in the Billable box. That's the reason that the item you've created comes into the invoice at a cost. Additionally, the posting of the account depends on what information you've documented when creating the item.

On the other hand, if wish to manually add the items to an invoice to get the correct sale price, I suggest creating instead an item on the Product and services page. Then, delete the created on the Time Activity to ensure your billing metrics are not accurate.

Here's how to add item on the product and service:

1. Go to Get paid & pay or Sales and select Products and services.
2. Click New. Then, choose Inventory, Non-inventory or Service.
3. Enter a Name for the product or service.
4. From the Category dropdown, select the category that best describes your product or service.
5. If you sell the item, confirm the checkbox is selected for I sell this product/service to my customers. 
6. In the Description on sales forms field, enter a description. This is what your customers will see on their sales form.
7. Enter an amount in the Sales price/rate field. 
8. Select the Income account dropdown and the account you want to use to track the sale. 
9. Fill in the other necessary field.
10. Click Save and Close.

Then, please follow the steps below on how you can delete the created items from time and costs.

1.  Go to the Project menu in the left panel.
2. Choose the created time cost. Then, double-click it to appear the Time cost report.
3. Click the item under the Product/Service column.
4. Choose Delete at the bottom.
5. Click Yes to confirm.

Lastly, you may refer to this article to see different details on how the Sales page gives you a great at-a-glance view of all the status of your sales transactions like open and paid invoices: View sales transactions.

Please know that you can always get back to us if you have any other clarifications or questions about managing items for invoices in QBO. I'm always here to help, AVadmin. Have a great day!