There is a big difference between a parcel and freight. UPS is a parcel service - no equipment on the truck, no fork lift, can run through sorting machines, can be carried by one delivery man. I don't know the rules, but I know you cannot have a 6 foot (or 12 foot) piece of lumber, and I believe the package must be under 70 pounds.
A freight item, whether carried by a trucker or UPS Freight or FedEx Freight is a different game - think fork lift, and go from there. The last time I got some lumber shipped to me, the dealer had negotiated a 83% discount - only paid 17% of the price I would have had to pay. Don't expect to get a good price if you are not a volume shipper.
An option that sounds attractive, that I have only used once, is
www.uship.com - You describe what you want to ship, from where, to where, when, and the truckers with space will bid on it. Whether it be a room of furniture, a motorcycle, a live horse that has to be walked every 6 hours, or what. I specified a blanket wrapped piece of custom furniture, delivered upstairs in NYC, etc. Great service at a good price. I have wondered what response I would get if I specified a couple hundred board feet of lumber, up to 10 feet long, must be kept dry, 1000 pounds, etc. etc.