Setting up your products and services is made simple in QuickBooks Online. In just a few clicks you can add inventory, non-inventory, services, and bundle items. I'd be happy to shed some light about how to structure the pricing of your products if it's not the same each time it's purchased.
If your customers all pay a different price for a product, you'll want to leave the price field blank when you set up your product/service. This will ensure that each time you invoice a customer, you can manually add the price that suits their profile.
At this time, there's no way to set up individual prices for each customer when selling your products/services. You can either manually enter different prices each time the product/service is purchased, or you can create separate product/service items with their corresponding sale price.
I think having the option to set up default sale prices for individual customers would be really beneficial, not just for you and your business but for other users as well. I'd be happy to pass along your suggestions to my team. I'd encourage you to submit your thoughts as well by clicking the Gear icon > Feedback. These messages get sent straight to our engineering team, and they're read daily.
I hope this helps clear things up for you.
Have a great day.
Consider using an inventory management app with B2B platform to set many different prices to your customers and integrate it with your QBO.
Just my 2 cents.