How much to spend on a 8year old birthday present?

[LittleSugaPlum]

AIBU in thinking that £80-150 is way too much to spend on your childs birthday present at 8years old?

Mine get lots of little things for xmas, to me their birthday is more important.
Ds1 had a bike for his 8th, around £100, and a 3DS for his 9th, again around £100.
He looks after both and gets a lot of use out of them.
I don't understand why anyone cares what others do.
If no one brought these things for xmas and bdays when would they buy them.