The base price of the 3DS XL is still higher than the NDS ever cost in general, isn't it? Yeah, there were sales, but even still, the NDS didn't take off big time until it was $129 as I recall. I think there is still room for growth in 2014, at least in the US.
I don't think they can afford a price drop on 3DS XL right now... it's not like it's components are getting cheaper at the same pace as smartphone ones. It would be better for them to introduce a new handheld in 2015 (releasing it on 2016).