The Midnight Purple 3DS will retail at $169.99, like every other 3DS, and will be released on May 20th, the same day as Mario Tennis Open launches, not that the two seem particularly connected like another dual release might have been:
Clearly, Majora’s Mask decals need to made in order to make my old mockup become a reality.
As of now this has only been announced by Nintendo of America, so there is no word yet on when it will become available elsewhere. However, this more than makes up for the fact that the Ice White 3DS has been available outside North America for months now.
Source: Nintendo PR