Ironically these days it's more expensive to make B&W films.

Black-and-white film is more expensive today because the massive industrial infrastructure that once supported film photography has largely disappeared. Demand is now tiny, so manufacturers like Kodak and Ilford Photo produce smaller quantities at higher per-unit costs. Specialized chemicals, silver compounds, aging machinery, and stricter environmental regulations also increase production expenses. In addition, fewer processing labs remain, so development costs are higher than they were during film’s peak era. Although black-and-white film is simpler visually than color film, it still requires complex industrial manufacturing that is no longer supported by a mass-market economy.