More affordable alternatives to Skinceuticals?

Hello WIMJ folks, so happy I've discovered this site!

I've been gifted a full Skinceuticals anti-aging regimen for my birthday about 4 months ago (I know, a super generous gift!). I've noticed a difference in my skin for sure. The products are running low now, and I wanted to re-purchase, and then I saw the price tag 🤯. I am wondering if there are alternatives that are as effective but are in the mid price range? I do not mind investing into my skin, but $160 for a bottle blows my mind. I live in California. I have normal, slightly oily skin, and an olive skin tone with some darker marks I guess from sun.