Slaves and the Megillah

I was learning alongside a student of mine, who for purposes of this post will be called Yankel, when I realized the following thing.

It had always bothered me that Esther made the following statement:

ג וַתַּעַן אֶסְתֵּר הַמַּלְכָּה, וַתֹּאמַר--אִם-מָצָאתִי חֵן בְּעֵינֶיךָ הַמֶּלֶךְ, וְאִם-עַל-הַמֶּלֶךְ טוֹב: תִּנָּתֶן-לִי נַפְשִׁי בִּשְׁאֵלָתִי, וְעַמִּי בְּבַקָּשָׁתִי. 3 Then Esther the queen answered and said: 'If I have found favour in thy sight, O king, and if it please the king, let my life be given me at my petition, and my people at my request;
ד כִּי נִמְכַּרְנוּ אֲנִי וְעַמִּי, לְהַשְׁמִיד לַהֲרוֹג וּלְאַבֵּד; וְאִלּוּ לַעֲבָדִים וְלִשְׁפָחוֹת נִמְכַּרְנוּ, הֶחֱרַשְׁתִּי--כִּי אֵין הַצָּר שֹׁוֶה, בְּנֵזֶק הַמֶּלֶךְ. {ס} 4 for we are sold, I and my people, to be destroyed, to be slain, and to perish. But if we had been sold for bondmen and bondwomen, I had held my peace, for the adversary is not worthy that the king be endamaged.' (Esther 7:3-4)

Why would Esther have been okay with having the Jews sold as slaves? It's obvious why she's not happy about their extermination, but why is slaving okay?

The answer to this question occurred to me due to my student reminding me of the following tale regarding Mordechai and Haman based on Megillah 15a: "There was a tradition that Mordecai once went with a deputation to the king of Persia to ask permission for the Jews to rebuild the Temple, v. Jast. [Rashi: One (Mordecai) came as a rich man, the other (Haman) as a debtor. Haman according to the legend had sold himself during one of the wars as a slave to Mordecai for a loaf of bread.]"

Per the more elaborate rendering of this legend in Legends of the Jews by Louis Ginzberg, Mordechai used to show his shoe and/or his kneecap, where the contract had been written regarding Haman selling himself as a slave to Mordechai, which provoked him.

What is clear to me now is that Esther is saying the following: "I understand that Haman was incensed by Mordechai's constantly reminding him that he once sold himself as a slave to Mordechai. Therefore, it would have been understandable if Haman in return decided to enslave Mordechai and all the Jews. However, Haman has gone even farther than that and has decided to exterminate the Jews. At this point, I must step in."