It's taken me years to find out what works for my skin. Some people get on well with drugstore by pure chance I think. I use drugstore to cleanse and moisturise and spend more money on serums. Unfortunately with some things ( serums for example) you have to give them a good run out to see if they are making any difference so it takes a while before you realise you need to try something else.
Paula's Choice is very very good - if you have bought the 2% BHA I've not found another product to equal it.
However even Paula will tell you some things aren't worth spending money on - cleanser is on your face for seconds only, definitely not worth spending more for fancy ingredients your skin won't notice. Basic components of moisturiser not changed in years so high end comes with a massive markup. Serums worth spending money on if you actually know what you are buying and what you want to put on your skin, otherwise 'a good serum' could be a waste of money as it may not do what you want and everything is called a serum now, whether it is or not.
And I'm sure all the products were Paula's own and that her list was very comprehensive! Not daft, our Paula.
Some of her products are very very good, but do be aware that that's what she'll tell you!
Why don't you ask the skincare thread gurus for an analysis and recommendation? (they have a wee snail on their thread at the moment!) Their advice is fantastic! I got some products from The Ordinary (very reasonably priced for "scientifically advanced" skincare- especially serums) and am enjoying finding out what works and what doesn't.
I think some expensive products are worth it, and some aren't. Personally, I use one (for me) mega expensive product which is L'Occitane Divine Cream as a facial moisturiser but also use Astral at about £3 for a bucket sized pot. The stuff I raise an eyebrow at is the sort of mid-priced stuff- the Olay Regenerist etc type of prices. Likewise oils etc. Organic rosehip from Naissance- about a fiver. Trilogy in a fancyschmancy box £20. Go figure.