I've used Bana Boxes for years.
They have a massive plant in the middle of rural Texas, right no 287 near I-35.
This means their prices tend to be orders of magnitude lower than other companies + close I-35 access means shipping is cheap + fast.
Ask for Marshall Boenker @ 817-919-3589 for assistance.
They also do box printing, so you can print Amazon AISN numbers or UPC numbers right on boxes, to meet box pull requirements of large companies.