Olaplex vs. Kerastase vs. Ouai (or others??)

hi everyone, i’m looking to start taking real care of my hair (i’ve had some bouts of depression and stuff and just stick to head and shoulders usually, but i know this isn’t good). i’ve heard recommendations for olaplex, kerastase and ouai, but i’m not sure which ones are best and i don’t have a ton of money for trial and error.

i did take the hair quizzes on each website, but i kind of felt like they weren’t able to address all of the things i want to work on. so for more info, i have: - fine hair, but a lot of it - wavy - oily scalp that also has some dandruff/flaking - wash my hair about every 2 days - frizzyyyyyy - not dyed, i pretty much only use heat on special occasions (3-4 times per year) - i pretty much just brush and go.

I especially want to work on the frizz/defining my waves while helping my oily scalp and the flaking. any recommendations are welcome!! please help!!