Generally, FedEx has the cheapest shipping cost.
Easiest way to do this is find similar size boxes, then package the sign. After it's packaged, weigh yourself on your bathroom type scale. Then weigh yourself with the box and subtract your weight. You'll know what the box weighs. After that, measure the box (width, height, length) and go online to get a shipping quote. You can try all three carriers to see who has the cheapest rate (UPS, FedEx, USPS). Usually, FedEx and USPS will be the lowest. However, USPS has a "girth" size, which FedEx doesn't.
Also, any UPS or FedEx agent will charge a surcharge. They mark up the actual cost to make a profit. You'll get better prices directly at a UPS or FedEx owned store.
That's how I do it and I'm usually within a few dollars from actual cost.
Last edited by badgas; Thu Jul 29 2010 03:40 PM.