Pirate Ship offers super cheap USPS rates—up to 87% off the post office—which...

https://technivorz.com/does-shippo-really-offer-strong-ups-rates-compared-to-other-tools/

Pirate Ship offers super cheap USPS rates—up to 87% off the post office—which makes it a top pick for sellers focused on USPS. But if you need DHL Express or prefer live chat support over email-only help, Shippo might be your better bet