[photochemsyn]

Well, it would make a lot more sense for the wealthy class to have their own stem cells harvested at a young age then cryogenically store those stem cells and use them to seed artificial blood generation systems.

From this perspective, things look different. i.e. less sinister. A holy grail of biomedical genetics is the ability to create whole blood - white cells and all - from a patient's stem cells, as that would eliminate the need for blood transfusions as well as all problems related to any kind of incompatibility. Still seems to be a ways off, as blood generation is another one of those ridiculously complicated biological systems, and is also closely interwoven with the immune system (since pathogens tend to show up and spread via the bloodstream).

Now, maybe the easiest way to do this is with 'Dolly the Sheep' tactics, meaning wealthy people would create clones of themselves and then harvest blood and organs from those clones, as in at least one dystopian movie.