code: protected function refreshProductSellPrices(ProductInterface $product)
      {
          $sellPrice             = $product->getSellPrice();
          $grossAmount           = $sellPrice->getGrossAmount();
          $discountedGrossAmount = $sellPrice->getDiscountedGrossAmount();
          $taxRate               = $product->getSellPriceTax()->getValue();
          $netAmount             = TaxHelper::calculateNetPrice($grossAmount, $taxRate);
          $discountedNetAmount   = TaxHelper::calculateNetPrice($discountedGrossAmount, $taxRate);
          
          $sellPrice->setTaxRate($taxRate);
          $sellPrice->setTaxAmount($grossAmount - $netAmount);
          $sellPrice->setNetAmount($netAmount);
          $sellPrice->setDiscountedTaxAmount($discountedGrossAmount - $discountedNetAmount);
          $sellPrice->setDiscountedNetAmount($discountedNetAmount);
      }
docs: Recalculates sell prices for product
  
  @param ProductInterface $product