I don't believe in children having heaps of toys so we buy 1 or 2 things for birthday and Christmas depending on what I think they'll like (and when they're older they'll be able to tell me) and usually end up spending between 100 - 200 dollars each time. Mostly on big things though.. for example, for Chrstimas my DD is getting a wooden kitchen, saucepans/kitchen set to go with it/apron, hat & Gloves and some play food for the cupboards - all up I think it was about 170. That's all she's getting.
We do spend quite a bit on their birthday party though.. Her birthday party usually costs me about $200 - $300 which includes hall hire, food, birthday cake, etc.