Update savings plan commitment amount guidance

Added note about purchasing savings plans and reservations.

Author: nwokolo

articles/cost-management-billing/savings-plan/choose-commitment-amount.md

@@ -15,6 +15,8 @@ ms.author: onwokolo
 
 Savings plan purchase recommendations are calculated by analyzing your hourly pay-as-you-go usage and cost data. Recommendations are generated for the selected savings plan term (1- or 3-years), [benefit scope](scope-savings-plan.md) (shared, subscription  and look back period (7-, 30-, or 60-days). Azure calculates your potential savings by simulating the total costs you would have under a savings plan. It examines each combination of term, benefit scope, and look back period. It then compares these simulated costs with the actual pay-as-you-go costs you incurred. The commitment amount that returns the greatest savings for each term, benefit scope and look back period combination is highlighted. To learn more about how recommendations are generated, see [How savings plan recommendations are generated](purchase-recommendations.md#how-savings-plan-recommendations-are-generated).
 
+Some compute products can benefit from both savings plans and reservations. If you buy either a savings plan or a reservation, allow at least X days for recommendation systems to update and reflect your purchase before considering the other option. Avoid purchasing both products at the same time to ensure recommendations are accurate and to maximize your savings.
+
 Azure doesn't currently provide savings plan recommendations for management groups. For more information, see [Recommendations for management groups](choose-commitment-amount.md#recommendations-for-management-groups).
 
 Savings plan recommendations are available in [Azure Advisor](https://portal.azure.com/#view/Microsoft_Azure_Expert/AdvisorMenuBlade/~/Cost), the [Azure portal](https://portal.azure.com/), and the [Savings plan benefit recommendations API](/rest/api/cost-management/benefit-recommendations/list).