Pirate Ship delivers great USPS discounts—up to 87% off—making it a solid...

https://blogfreely.net/murciajpvo/shippo-for-amazon-and-ebay-can-it-manage-both-channels

Pirate Ship delivers great USPS discounts—up to 87% off—making it a solid choice if you mainly ship with USPS. Support is email-only, which might slow down help. Shippo steps in better if you need DHL Express or want more carrier options