Buddy's goal is to play himself into the first round. A lot of players have played themselves into lottery picks by coming back for a 3rd or 4th year.
And many of these have been undersized players.
Randy Foye, JJ Redick, Kirk Hinrich, Hersey Hawkins, Andre Miller all returned as Seniors to significantly improve their games and make it into the lottery. Mookie didn't make it into the lottery but improved his position several spots by coming back.
Some other undersized players foresook coming out their soph years to make it into the lottery their junior years. Guys like Raymond Felton, Ben Gordon, Devon Harris, Rumeal Robinson, Rip Hamilton and Ray Allen.
Whether he comes back or not, I think, depends on whether the scouts think he's ready. But, if he's on the second round fence and if he can improve whatever deficiencies necessary to make the jump, then it could be worth millions for him to return.