The quite powerful Anker 737 sports a maximum output of 140 watts and has now been put on sale for US$99, which is a reasonable price for a high-end power bank that is designed for enthusiasts who own multiple power-hungry devices.https://www.notebookcheck.net/Anker-737-power-bank-with-24-000-mAh-receives-33-discount.702475.0.html
I've had one for ~6 months, like it a lot and would buy again (@$99 of course).