Final updates to Copilot Credit Pre-Purchase Plan documentation

- Updated documentation content and formatting
- Refreshed screenshot image for current UI
- Ready for PR submission

Author: pri-mittal

articles/cost-management-billing/reservations/copilot-credit-p3.md

@@ -29,7 +29,7 @@ To buy a pre-purchase plan, you must have one of the following Azure subscriptio
 
 To get started, estimate your expected Copilot Credit usage. This helps you determine the appropriate size for your pre-purchase plan. Each pre-purchase plan has a one-year term.
 
-For example, suppose you expect to consume 1,500,000 Copilot Credit with custom agents created in Microsoft Copilot Studio. At the pay-as-you-go rate, this will cost $15,000. By purchasing Tier 2 (15,000 CU) pre-purchase plan, the cost is reduced to $14,100 – a 6% saving compared to the pay-as-you-go rate for the same usage.
+For example, suppose you expect to consume 1,500,000 Copilot Credit with custom agents created in Microsoft Copilot Studio. Assuming the pay-as-you-go rate for Copilot Credit to be $0.01, then at the pay-as-you-go rate, this will cost $15,000. By purchasing Tier 2 (15,000 CU) pre-purchase plan, let's say the cost of that tier is $14,100, it will give a 6% saving compared to the pay-as-you-go rate for the same usage.
 
 ## Purchase Copilot Credit commit units