The whole “spend money to get your book translated” thing is fake, it’s just a way to get you to spend money on books instead of using piracy sites. The editors choose which books keep getting translated, nothing else. The editors are probably prone to choosing a popular book though, since it means that they earn more.
So even if your favorite book is immensely popular, the most popular among trial reads, if no editor chooses it then it’s just gone.