A Compute Savings Plan and changing instance family to a less expensive

Question

Greetings,

**Scenario**: A t2.medium instance was covered by an instance savings plan that has just expired. The t2.medium instance is expected to be converted to a less expensive t3a.medium in two months. 
A compute savings plan seems to be appropriate, since it allows changing instance family during the term.

**Rates**: For compute savings plans, t2.medium rate is $0.0489/hour while t3a.medium costs $0.0437/hour. Assuming  a 1 year term. [Source](https://aws.amazon.com/savingsplans/compute-pricing/).

**Question**: what should hourly rate commitment be for a savings plan for this scenario, optimally? Can I specify the lowest one? ($0.0437)

Thanks.

Accepted Answer

Compute Savings Plan (CSP) can cover EC2 instances, Lambdas and Fargate. Also, CSPs can be shared across accounts within an AWS Organization. Your question is about a single instance, so I will assume that you have no other compute resources (EC2, Lambda, Fargate) across your AWS Organization. If you know that you will be moving to a less expensive instance type/size, then you can commit to the lower rate. Whatever can be covered by the CSP will be covered and the rest will be charged at the on-demand rate. You should know, however, that if there are other compute resources that can give a better discount, the CSP will be applied there first [1].

[1] https://docs.aws.amazon.com/savingsplans/latest/userguide/sp-applying.html

Answer

We took out a savings plan for our EC2 instances.  It was no upfront fee and a 3 year commitment.  We have a little less than 2 years left on the agreement.  If we resell it on the marketplace how does that fee structure change.  I assume:
* Since we paid $0 upfront we would receive no proceeds from the sale.
* Since the buy will be paying a reduced rate to AWS we would be responsible for the delta between our current rates and theirs.
Am I correct?

A Compute Savings Plan and changing instance family to a less expensive

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