CVS Pharmacy plans to overhaul how it prices prescription drugs, doing away with the complex and often-opaque formulas that typically govern what patients pay for medications. Under a system announced Tuesday, which it calls CostVantage, CVS said it will price drugs based on cost, a set markup and a fee to cover pharmacy services. The company said the format is designed to ensure medication prices more closely reflect their "true net cost."Subscribe to The Post Most newsletter for the most impor