Is the Dermorepubliq 10% Niacinamide Serum effective for its affordable price?

At one point in my life, I've once believed that expensive products are way, way better. After all, higher price point entails better ingredients, well thought of packaging, more accurate testing and research - right? But through countless products testing and doing my own researches, I found out and proved that it is not always the case. Yes, they may be good bu…