https://www.pewtrusts.org/en/research-and-analysis/fact-sheets/2013/11/11/persuading-the-prescribers-pharmaceutical-industry-marketing-and-its-influence-on-phys

https://www.pewtrusts.org/en/research-and-analysis/fact-sheets/2013/11/11/persuading-the-prescribers-pharmaceutical-industry-marketing-and-its-influence-on-physicians-and-patients https://www.pewtrusts.org/en/research-and-analysis/fact-shee... puts recent spending around $5 billion on samples. Seems reasonable for actual cost, not retail.