We got a raised eyebrow and a "oooh this one is NICE" for my TI-84+ but she didn't actually question it. I did say that it was MINE and he was just borrowing it (which is true! although he's been borrowing it all year... lol) -- I think she was a little surprised that a kid his age would be given such an expensive calculator more than she was actually concerned about it being legal.
If I were buying one just for this, I really like the TI-30X-IIS because it has a two-line display, which really REALLY helped DS with his first test... He could double-check that he entered the equation correctly because it was still on the screen. Also it's cheap - like $15.
