Just jumping off your post tiredofthis.
First I was surprised at the brutality of the murder of Stephany (although we don't have all the details as of yet). My gut clenched up for her and for Natalee (and any other unknown victims). I had thought as did a few others that Beth was correct in what she thought about Natalee's death and that it was more than likely what we see called a soft kill. She was drugged, sexually assaulted and the suffocated (one of theories).
However, looking at these two young women that are what we could call known victims of Joran I'm not so sure anymore about a lot of conclusions that I had come to during Natalee's case.
I am still mulling over thoughts here so bear with me while I type out what is troubling me this morning please.
I do not think at this point in time that it can be assumed that the motive for Stephany's murder was money. I don't think the motive for Natalee's murder was sexual assault. (The only example that I can think of at this moment is Ted Bundy, even though we don't know that JVDS has murdered but two people---with men of that ilk it's about the hunt, the kill, the so called victory).
I think that it's possible that the game of getting these young ladies into his company (possible shared circumstances---using drugs on these two girls without their consent) Luring them away from a comfort zone. Faking them out that they were safe within his company and then turning on them to drop his mask and show the monster that lies beneath might have been motive.
The problem I have seen described with dealing with sociopaths that murder is that we can't understand why they do what they do unless we can get inside of their head. I'm just not sure at this time that we can assign the ordinary motives that we see everyday to JVDS.
Sorry for such a long post! I'm still trying to puzzle out all of this.
All of the above is JMHO and not supported by links.
Surely the Kalpoe brothers are in a position where they could maybe bargain for the information? Or even his mother?