Are the cheap dupes really as good as SkinCeuticals C E Ferulic?

For the specific combination of 15–20% L-ascorbic acid, 1% vitamin E, and 0.5% ferulic acid, several budget formulas hit the same ingredient deck on paper. Specialist-subreddit consensus is that the active chemistry is closely comparable; what you give up at lower price points is typically packaging quality, stabilization, and texture. Whether that's worth the savings depends on how quickly you go through a bottle.