anonymous user Thanks for reaching it. Please find my inline answer below
Is the second region that we specify for the replication also Premium?
When you create APIM in Premium APIM then it will only create one unit in the primary region. You can add additional units either to the primary or secondary region and all the units that will be added would be of premium.
Are both regions charged at the same rates or is there a discount for the second region?
Additional incremental units (>1) either in the primary or secondary region will be charged 50% of the first unit purchased. If your APIM is created in the X region then the pricing of new units that are added in the primary/secondary region will be half of your X region pricing. For more details, please refer to the pricing document.
Can the account tier in the second replicated region be upgraded/downgraded? i.e. do we have any control over the second region given only the gateway of APIM exists there?
No, you cannot control the tier on newly added units either in the primary/secondary region as it is the part of premium SKU.
Feel free to get back to me if you have any queries or concerns.