Why does the Pasuk first say that the 'Egyptians' saw Sarah (12:14), and then that the officers of Pharaoh saw her?
Seforno: First it was the people who saw Sarah, and as Avraham had suspected, they began planning to 'buy' her. But when Pharaoh's officers spotted her, they decided that she was fit for the king.
Ramban: The Egyptians initially thought that Sarah was worthy to marry into the aristocracy of Egypt, so they handed her over to the king's officers. However, when the officers saw her dazzling beauty, they were afraid to lay a hand on her, and decided that she was fit for the king himself. 1
As Rashi and Targum Onkelus explain. According to Targum Yonasan, they told Pharaoh about her and he took her himself.
Why did the officers not first consult Avraham, to talk him into giving them Sarah, as was customary in those days, before taking Sarah to the palace?
QUESTIONS ON RASHI
Rashi writes: "'They praised her to Pharaoh'- [This means] they praised her among themselves, [saying,] 'She is fit for the king.'" But perhaps it means, "they spoke her praises before Pharaoh"?
Gur Aryeh #1: The verse does not state that "Pharaoh took" her (as it does later by Avimelech (20:2)), but rather that she "was taken," i.e. by the officers, of their own initiative.
Gur Aryeh #2: If so, it would have been more correct to write, "they praised her before Pharaoh ('Lifnei (or Bifnei) Par'oh', rather than 'El Par'oh')."