One who learns for a goal other than these is not learning Torah "for its own sake." Rather, he is learning for the sake of a reward - that is, for the sake of some benefit that he will get from the information.91
91 This difference can be seen from what Rambam writes, that the study of Torah is forbidden to a Gentile, as is the observance of a sabbath, because of the prohibition of adding a new commandment or religion. Even though the Talmud in Tractate Sanhedrin 59a says that this is like "having relations with a betrothed woman," or "stealing from the Jews," it appears that its intention is only regarding such a depth of Torah study that it is severely prohibited, more so than the general restriction that Gentiles should not take upon themselves an additional observance in a manner of a Divine commandment. Therefore, a Gentile who delves in Torah study to that extent is violating two prohibitions: (1) the general prohibition of adding a commandment, and (2) the specific prohibition of learning Torah in such depth that it is like having relations with "a betrothed woman" (a metaphor for the Torah), or stealing that which belongs to someone else (the Jewish people) (the Divine Code by Rabbi Moshe Weiner, Ask Noah International, 2018, p 72).