Before this whole line with the gold mine, you can take part in an auction and buy a slave girl. But for this you need to have 100,000 credits. In addition, it is not yet clear why you need to do this - there is no development of events later.
Another possible option - to become a slave to King Sauel - has not yet been implemented.
I can also say that the game was supposed to give two more options: 1) kidnap Don with the help of Arlene and hand him over to Sonya for her strange experiments with worms (probably a bad ending); 2) persuade Sonya to take part in her own experiment as a guinea pig. Whether this will be implemented - I do not know.