How do extra message packs work?

A message pack adds 100 chat messages. Its purchase screen shows your local price before payment. The US price is $2.99. You can buy a pack from your account with a subscription.

Pack messages do not expire, stay through plan changes and remain after the subscription ends. Without a subscription, chat is available for that remaining balance with Start's context. Carried-over and monthly messages are spent before the pack. A pack does not include a higher plan's features. Deleting the account removes any unused balance.