Unfortunately my DD isn't Invited to school "parties" as the parents know shes diabetic and don't want the "extra work" that comes with it.

If she started to go to some I would aim to spend $10 or so. I guess also depends how close they are. I would look at buying books, puzzles, craft type things and would generally steer clear of character things (I do the same for my DD)

It's my nieces birthday this week and for 3 presents (one from my mum as she's in england, one from DD and one from myself, I only spent around $60) so I definitely couldn't justify spending the same on someone from school