Thumb Score: +28

Woot! [woot.com] has seaistar Portable Charger Power Bank 50000mAh, USB-C PD 30W (Gray) for $14.99.
Shipping is free for Amazon Prime Members (must login with your Amazon account and select a shipping address in order for Woot to apply free shipping) or is otherwise $6 per order.

Price:
$35.01 lower (70% savings) than the reference price of $50