Sometimes stores have makeup samples. You can ask the makeup counter maybe they have a little sample that you can use for Purim.
If you’re honest about why, then I think it would be permitted halachically (though maybe ask your LOR).
Why not buy inexpensive 99-cent makeup.
Edit***
***You can ask the person working at the makeup counter if maybe they have a sample that you can have to use for Purim.
(Thank you)