Era coin expire

Everything gets converted to the currency you can use in the shop.  However, it's a very poor exchange rate, so it's not something you should save purposely.  

Hey Sawbolchevique​,

Thanks for your question.

For the Era currency, the one you can use to buy shipments, this does not expire.

However, the Era leveling currency (used to level your characters) is converted into Era currency at the end of the event.

Hope that clears things up!