Send With SES pricing is simple. You are not charged based on the number of contacts you have. In fact, you can have unlimited contacts.
In addition, you will incur AWS charges if you cross the below free tiers. (AWS will bill you directly).
- Email Charges: 3000 Free/Month. Then $1 per 10,000 Emails.
- Push Notification Charges: 1 Million Free/Month. Then $1/Million Push Notifications.