Great serum but pricey for the amount in the bottle

I have been using the serum in combination with the Shiseido Benefiance Cream. I really noticed a difference in how my skin looks. Not sure though if it is the combination or just the night cream and how great it is at providing moisture to my skin. I did not purchase more serum so I guess I will see this month how things go by just using the cream. I like this product...don't get me wrong but I found it more expensive than I can afford!