There is no reason on Earth why the actual costs to process the legal paperwork should cost more for one race of children than for another. It's obvious that some prices go way above & beyond actual costs and this reveals the ugly, greedy truth. Some children are in higher demand and can command higher price tags which translate into higher profit margins for those who work as legal child brokers. And it's obvious they are not above milking that to the highest potential the market will absorb.
Your example is by no means an isolated case of advertising children for sale either. (see my sources for another example of price discrepancies from various private agencies) Sadly, there are 100's, if not 1000's of sites online just like these which conclude your same point.
It sends a very clear message as to exactly who are considered the more highly-coveted children. As for how a child would feel in the opposite groups, I believe it could unnecessarily chip away at their self-esteem to realize they were the basement bargain and for reasons that have nothing to do with their actual value as a person & everything to do with the way society shallowly judges people based upon their skin color. Even the children in the highest inflated price groups could be offended that someone exploited both them & their first families by profitting off of their situation. You ask how we feel about those who participate in this industry. I am totally disgusted by it.
A related note while we're on the subject - if this is not trafficking in the human industry, then I don't know what is. The last time I checked, buying & selling any human being in the U.S. was outlawed in the 1860's with the abolition of slavery. Apparently it's acceptable to overlook that when you call it "adoption." It's not fair to children. All people should be equally valued, protected, & respected, not reduced to items on a human menu.
The UK & Australia, among other places, have already recognized the ethical problems associated with selling children through private agencies and have eliminated them altogether. Adoption works as a true social service there with nobody profitting any amount from the sale of children. Totally removing the profit aspects from the U.S. adoption industry is necessary in order to restore it to a social service for children instead of the huge, unregulated business oppportunity for adults which it currently is.
You're right - it IS based upon supply & demand. And it IS racism. Thanks for bringing up a question on this absolutely disgraceful practice. I wish more people would question it & refuse to participate in it.