If 2% of your income, or $70 (.02 * $3500) is going to cause you issues, you might want to reexamine your finances.
But no, you don't need a smart phone. They're nice to have, but not necessary to succeed in flight school.
Not going to cause issues, my finances are just fine. I just hate spending money on things that aren't booze or things that don't shoot. Mabye I should join the real world...I don't want to be an old man at 21. Just curious as to how smartphones workout in flight school. I have a pretty good idea now. Thanks, Sir.