When I bought bought mine forever ago, it was about $150. And just how do you think you get that scope-mounted bubble level to be level? Your scope has to be dead-nuts level along with that level, to ensure that your crosshairs are as close to 100% level as possible, or else you will start having issues the further out you go. Your logic is flawed, unless you don't plan on shooting beyond 200 yards. If you're not a complete idiot and a complete noob, then you have a general idea of where your scope needs to sit for your proper eye relief. This device sets reticle plumb to gravity. Only super-shitty scopes are the reticles not plumb to level with the optic's turrets.
Well, in my life, I've mounted thousands of scopes, most of which when I worked at a small local gun store doing professional work being trained by professionals. So, I know WTF I'm doing. You don't have to think it's worth the money, but you also probably have never used one, either... You probably think your half-empty milk jug at 50 yards is a scientific guarantee, as well.
My point being, it works. Unless you own one, and have used one, don't knock it until you've tried it. Speak from experience, not from bullshit you read on the interwebz.