My coworker was a snowboarder until a few years ago -- now he is a sit skier. Knowing that I am ski-obsessed, he asked me where one might buy single skis. I was pretty stumped. Last year was his first season out West and felt like he began to find the speed limits of his current ski.
Sure he could buy a pair like all the rest of us, but the likelihood of him destroying a ski or wearing one out is pretty minimal. Besides I'll probably end up convincing him that he needs at least a couple skis mounted with quiver killers ;).