I would get the son a nice gift and a few smaller ones. The daughter could get small gifts. I don't think I would spend $200 a piece on them at this age.
When the kids were younger and you could get catalogs for Christmas we would give the kids each a colored crayon and let them mark away. Afterwards we woud go over all the marked items and decide what would go with them and how many. They were thrilled because they didn't know what they were getting from the book(s) but they knew they would get something.
We used to get our son one of the big items and a few small gifts. Our daughter got smaller gifts. Each had the same amount spent on them. Our son asked why sister had more gifts than he (13) and we explained to him that he always wanted the big things and that she didn't ask for anything special and was happy with what she got.
Don't start something that you can't continue in the future. Christmas is about the child and not about gifts only.
Maybe you coud do a special trip to a museum or something as part of a gift.
Have a great holiday season.
The other S.
PS I once went to a cousin's house that bought her 1 year old every gift under the sun and it looked like a toy store in the house for Christmas. There was no way possible that that kid could play with everything without outgrowing most of it. Definitely person gone overboard. You couldn't walk in the room beause of the stuff.