You buy one, then another, yet another, and then many more. Sell the ones you don’t like. They all have their own personalities. If you buy a used one on BST you can generally resell it for a similar price if its still in good condition. The most popular size is 240mm, significantly shorter is a tough sell.*1. How would I go about figuring out which grinds and profiles I like?
It might blow your mind but there are people here that buy dozens in a year and may sell most or all of them. Keeping a knife for a few weeks then selling it is entirely normal here.