Just like airplanes take off and land, shares of Spirit Airlines (SAVE -18.18%) have taken shareholders on a ride. Only in this instance, there has been ridiculous amounts of turbulence on the journey.The business has made for a terrible investment. This airline stock currently trades 98% off its all-time high, a milestone that was achieved nearly 10 years ago. At this beaten-down level, is it time to buy Spirit Airlines?Up and downThings briefly reversed course recently. From Oct. 18 to Nov. 11, shares of ...