This helps to explain why drug prices from top wholesalers were lower than the suggested wholesale prices in the guidebook. If a price war among drug wholesalers began shortly before the study was conducted, it could have caused the studied prices to be lower than usual.

This does not help to explain why prices for the 300 most common drugs were lower than the suggested prices in the guidebook. Since we're only talking about these 300 drugs, it doesn't matter if suggested prices for less common drugs are usually higher.

This helps to explain why drug prices from top wholesalers were lower than the suggested wholesale prices in the guidebook. If wholesale drug prices fluctuate significantly each month, it makes sense that the annual guidebook might not reflect the prices for any given month.

This helps explain the difference in the actual and suggested prices. The guidebook prices allow wholesalers to make a profit, so they can still profit by charging 60-80% of the suggested price. Wholesalers might want to charge less to stay competitive or reduce consumer costs.

This helps to explain why drug prices from top wholesalers were lower than the suggested wholesale prices in the guidebook. If the suggested prices are for smaller sales to individual doctors, these wholesalers who specialize in bulk sales might charge less for bulk purchases.