Craft Challenges

Why can’t you turn excess inventory earned into SP’s in order to complete the challenge and win the Grand Prize? I haven’t done the calculations yet, but I’m going to assume  you can achieve the Grand Prize without spending real cash; however, I think its near impossible unless you do not sleep for 10 days and do not miss more than a few minutes during “shift change” ha! Is there a trick? A cheat? I’m so frustrated with this game and all the pressure to make purchases to succeed! Great way to prep young adults for the real world…no matter how hard you work unless you have money you’re not going to win. Sad EA…