With new advances in medical technology, it's now possible for the Ultra-Rich to grow custom body parts and have them easily transplanted.
The Mega-Rich might have to pull a few strings.
However, the Super-Rich are not so fortunate. Costs must be cut somewhere, and they'll be damned if they're going to reduce the quality of the product. So the product is often found from natural sources.
If you frequent bordellos and have a choice unit, watch your back. Some say the Peepee Kings are an urban legend, but that's just an urban legend.