YABU.
I think it is too little,sorry.
Although,I do think that there are many people who do go the opposite way,too & there is no need to go mad or into debt.
However,scrimping on toys to save money on decorating in the new year sounds a bit harsh.
I think any child would rather have more toys,books,craft stuff,etc. than a colour-co-ordinated,interior design inspired room.
Decor usually only interests/impresses adults not young kids.
If your child would rather forego Christmas presents for her bedroom decor I would be very surprised.
Although,if she was a teenager I could understand that,just not a wee girl that is at the age to enjoy My Little Pony.
Another point,is that it isn't exactly a surprise that Christmas has come upon us again...it's on exactly the same day of the year,every year.Many people even on low incomes manage to understand this & budget & prepare appropriately.
I have a feeling I shall soon feel the wrath of Mumsnet!