What on earth could possibly justify that much for some folded cardboard? Other spots had similar size boxes and even heavy duty ones for $5 each. Is there some secret handshake or membership that takes the price down back to normal?

I am moving from the east coast to the west coast. The cheapest U-haul container costs over $1500. So, I decided to use UPS to ship my stuff.

I've packaged my stuff into scrap Amazon boxes of various sizes. But now I face a dilemma. It seems that the bigger the box, the cheaper it is to ship.

For example, a 20x20x20 inch, 50lbs box costs $60.15. A 20x20x40, 100 lbs box costs $102.57, $17.73 cheaper.

If I manage to make more efficient use of space and package 150lbs into the 20x20x40 box, it is $141.16, less than a dollar per pound.

Of course, there are added cost of packaging. The biggest 20x20x40 box I can find on Amazon costs $80 for 5, whereas 20x20x20 costs $45 for 10. But I need at least one big box for the biggest item.

Smaller boxes are easier for me to pack and probably easier for USP to handle as well. But I might just have to ship it in a big and heavy box to save cost. What do you think I should do and does anyone know why UPS pricing encourages big and heavy boxes?