Death penalty for mere intent to sell?

Parshat Mishpatim lays out the death penalty for human traffickers. The pasuk reads:

16. And whoever kidnaps a man, and sells him, and he is found in his possession, shall surely be put to death.

טז. וְגֹנֵב אִישׁ וּמְכָרוֹ וְנִמְצָא בְיָדוֹ מוֹת יוּמָת:

I think we can parse this pasuk in at least three ways:

1. It speaks of one offender
2. of two offenders
3. of three offenders

According to (1), person A kidnapped X, sold X, and X is found in A's possession.
According to (2), person A kidnapped X, and then either sold X or still has X in his possession.
According to (3), person A kidnapped B, person C sold B, and person D has B in his possession (either conveying B from place to place or guarding him, or else by purchasing him).

According to Rashi, it is (1). The difficulty with this is that if A sold B, how can B still be be found in A's possession? Channeling the Mechilta, he explains:

and he is found in his possession: [I.e., this means] that witnesses saw him that he kidnapped him and sold him, and he [the kidnapped man] was found in his hand prior to the sale. -[From Mechilta]

ונמצא בידו: שראוהו עדים שגנבו ומכרו ונמצא בידו כבר קודם מכירה:

Perhaps we could alternatively imagine this as the kidnapper being caught in the act of selling, right after the money has been exchanged.

According to Ibn Ezra, it is (2). Thus:

ונמצא בידו -בשוק לפני המכרו יומת.

"And is found in his hand -- in the market, before he sells him, he shall be put to death."

In other words, whether he is found in his hand with intent to sell, he also gets the death penalty.

Ibn Caspi seems to say that it is (1). He who explains that the verb "selling" encompasses a range of actions:

"And sells him -- there are, of the verbs and movements [which inform] either [?] on the stirring up of the soul and the intent at the start; and there are those that are about the intermediate [actions], where its meaning is made clear by understanding of nature, that then it is the completed movement; and there are those which are about the completed movement. And here, the intent is upon the beginning of the movement [/action], that is the movement of the selling. And therefore it states 'and it was found in his hand', and this is where he kidnapped him and then hid him in a room of his house, or he conveys him to a specific place, and he could claim that his intent was not to sell him... behold, the matters are seen that his intent was to sell him, and therefore, he shall surely be put to death."

Perhaps we can read this into Ibn Ezra as well.

See also Ramban:

ויתכן שהיה עוד כסדרו, ונמצא בידו של לוקח, שאם גנב את הנפש והביאו לביתו והביא שם הלוקח ומכרו לו ולא הוציאו הלוקח משם אינו חייב שלא נגמר המכר ביניהן, או אפילו כשנגמר המכר יפטר, כמו שכתבתי:

My parse #3 was already explained above, but I'll describe it again. In human trafficking, there are often multiple actors. The initial kidnappers, those who transport the kidnapped person, and the sellers. Perhaps also the purchasers. Consider the sale of Yosef. He was snatched. He was conveyed by caravan to Egypt. And he was sold to Potiphar. (Yes, there was another sale / other sales along the way.)

It is an interesting, though perhaps already tired point, that the peshat interpretation of Ibn Ezra and Ibn Caspi are against the halacha.