You'll be charged a $30 upgrade fee if you purchase a new device at retail price or through the device payment program.
No, you won't be charged the activation fee in addition to the upgrade fee.
The activation fee is a one-time charge billed when establishing a new line of service. The upgrade fee applies when you purchase a new device to replace an old device on an existing line.
If you return the device within 14 days of the date of purchase, the upgrade fee will be refunded.