We like this a lot. At select locations, UPS Stores are selling two sizes of luggage boxes, according to a press release, "large and small; [each] has a sturdy handle for easy carrying, and is made of recyclable corrugate. Because it weighs less than an empty suitcase, packing directly into the box can help lower shipping costs. Travelers also can include packaging tape and a return UPS shipping label for use when returning home." Of course, you can always just put your stuff in a regular box and ship it. We couldn't find how much each box costs, but we did see that the maximum liability the UPS Stores will cover is $1000 per shipment, and only if a higher insurance premium is paid. Keep in mind that the airlines offer a higher level of protection if they lose or damage your luggage. So don't pack anything too valuable.
Clarification from UPS: "For the outbound trip, when the shipping is purchased at a The UPS Store location, the maximum liability is $50,000 (an automatic $100 in coverage with the option to purchase additional coverage). If a traveler chooses to purchase the return shipment at that time, then the maximum coverage on the return trip would be the $1,000 you mentioned in your post (considered a drop off package). If the traveler returns to a The UPS Store at their destination and purchases the shipping separate for the return trip, then it would be treated the same as the outbound shipment."