Skinceuticals Discount @ CGH Pharmacy

I was browsing through the CGH pharmacy website, intending to get another tube of La Roche-Posay Uvidea XL SPF50 PA+++ Tinted Cream, which is on discount now.

I was eyeing the Therapeutic Dermalogic Formula AHA Revitalizing Lotion 10% but it wasn't on discount, unfortunately.

I chanced upon Skinceuticals and they are having 15% discount now! I am planning to buy the Skinceuticals C E Ferulic or Phloretin CF. Anyone knows which one is better?