Can't let a low hanging resource go to waste. A matched kidney, heart, or other organ from a child could fetch millions from an elite in need. You don't even need to have a black market hospital in Thailand. You just get them bumped up the list a little. Then you start filling the waiting list with matches for the elite person. It might take a few kids before the donation reaches to elite, but eventually , they get their organ. On child abduction side, you need a data bases on a large population of children's genetic data. Through blood tests and biopsies you can obtain the data in the field. I am not an expert of transplant matching, but I would assume with the advances in genomic sequencing, one could gather the data in the field through simple blood and swatch samples. Then once a match is found, your do some voodoo on their identity, organ donor status and other legal paperwork. This part is most easily done using foreign children. There is quite a bit of natural obfuscation between records in one nation vs in another.