Thanks for joining the thread, @erins77. 

I'd be glad to answer your question. 

You're right. Importing new products to QuickBooks won't change your existing sales data.

You can utilize the pricing rules feature for your products and services in QuickBooks Online to offer discounts or charge different rates by item.

Here's how:

1. Go to the Gear ⚙ icon.
2. Choose Account and Settings or Company Settings.
3. Select the Sales tab.
4. In the Products and services section, click on Edit ✏️.
5. Tap to put checkmark for Turn on price rules Beta.
6. Select Save and then Done.

For creating price rules, check out this article for more information: Set price rules in QuickBooks Online.

For additional reference about managing your products and services, check out these articles:

• Adding Products and Services, Customers, and Vendors to Lists
• How to set up products & services

Please touch base with us if you need further assistance with inventory in QuickBooks Online. We'll always make sure to get back to you.