My Mulebuy Spreadsheet Adventure: Scoring the Ultraboost 21 for Less! Hey fashion fam! Let me spill the tea on how I snagged the iconic Ultraboost 21 using the Mulebuy Spreadsheet from 1688. If you’re all… How I Snagged the Ultraboost 21 Using the Mulebuy Spreadsheet: A Hassle-Free Shopping Guide