Is it haraam to buy pictures of male and female singers?

The basic principle with regard to pictures of animate
beings is that they are haraam, whether they are three-dimensional
(statues) or two-dimensional, such as pictures in frames, on clothing, or
otherwise. 

This has been discussed in the answer to question number no.
10668. In the answer to
question no. 143709, there is
a discussion of the ruling on buying clothing on which there are pictures. 

This prohibition has to do with the issue of making images,
regardless of whether there is anything in the picture itself that is
contrary to sharee‘ah in the first place. Pictures of scholars, men,
children or animals all come under this ruling; it is the picture itself
which is contrary to sharee‘ah. 

But if in addition to that the picture includes something
that is contrary to sharee‘ah, such as if it is a picture of a naked woman
or one who is showing part of her body, even if it is the face and hands,
then it is more haraam and a greater sin, because it includes another thing
that goes against sharee‘ah in addition to image-making. 

So how about if the picture is of those who promote evil and
spread immorality, such as actors, singers and the like, whose images are
traded in shops that promote evil and vice, to make sick hearts even more
attached to them? The one who knows the ruling on image-making will have no
doubt that they are haraam. Moreover, it is known what effect these pictures
have of filling the heart with infatuation and corrupting it. This is what
the questioner is expressing when he says “this is only because of love of
the artist”. What more do you want after that, O slave of Allah?! 

The Messenger of Allah (blessings and peace of Allah be upon
him) said: “The angels do not enter a house in which there is a dog or an
image.” Narrated by al-Bukhaari (3075) and Muslim (3930). 

See also the answer to question no.
13214. 

Once it is understood that it is haraam to keep these images,
we know that whatever Allah has forbidden, buying and selling it is also
haraam, and spending money on it is a waste of money and is a kind of
extravagance that is haraam. The Messenger of Allah (blessings and peace of
Allah be upon him) said: “May Allah curse the Jews. Animal fat was forbidden
to them, so they sold it and consumed its price. When Allah, may He be
glorified and exalted, forbids eating something, He also forbids its price.”
Narrated by Ahmad, 2546. 

See also the answer to question no.
49676 

And Allah knows best.