Here’s the truth. The real worth of Lightroom presets is governed by how much value the buyer will get from them.
That means, depending on the type of photography you do and how it rewards you, any given pack may be worth more to you than it is to me. Or less. I can’t possibly say.
But I can get you to ask yourself some questions to help you figure out if that Lightroom presets pack you’ve got your eye on is really worth the asking price. Come read, come learn.