On the opposite end of the spectrum, you should remember that it is not mandatory to purchase a special valise for carry-on items. A few sturdy garbage bags can work just fine.
You can also put things in boxes. Be sure to wrap them extremely securely with glass-reinforced tape, and recognize that they will get very rough handling. Furthermore, the airlines will not take responsibility for damaging anything in a cardboard box. You take your chances.
Backpacks and Camping Gear
You can ship camping-style backpacks as well. Some airlines will put them in large plastic bags to help keep things from tearing off. Otherwise, make sure that anything that you have attached to the pack (sleeping bag, tent, roll) is securely fastened. And, as with packing in cardboard boxes, airlines will not take responsibility for damaging anything in a backpack. Do not pack the good china in the backpack.