Greyhound Package Express is a good option for items this size. It is economical. The customer will have to pick up at the Greyhound nearest their home.
I've shipped items the size of the end table (e.g. antique sled) via FedEx Ground and it worked out well. You can tape two 22x22x22 boxes together to make the size you need.
I've also used Uship to ship a small sofa and it worked fine. You put in the size and weight of the furniture and then shippers contact you with quotes. Search the forums for Uship and you'll get lots of info.
Here we have those mailbox places that ship items you bring in. They use UPS,FEDEX, or USPS. They ask which one you want to use and they will tell you how much each company charges.