Complex sentence: The plaintiffs contend that the practices have driven up the wholesale cost of drugs for institutional buyers, including health insurers and government programs such as Medicaid, which in turn has cost taxpayers and insurance buyers billions of dollars.
Split into simpler sentences: The plaintiffs contended the practices had driven up the wholesale cost of drugs for institutional buyers, including health insurers and government programs such as Medicaid. That in turn has cost taxpayers and insurance buyers billions of dollars.