Good information has value. What value is up to the buyer. I like to gamble at pool. I have bought videos by Grady Matthews, Billy Incardona, and others where I could point to one or two shots that I learned that got me the cash.
All things being equal the player who has the benefit of coaching be it in person or through a video lesson will have the advantage. That's a given.
Take two people, a piece of leather, and five colors. The person who watches a video on coloring techniques will be rocking out well colored pieces in an hour while the other one is still trying to figure out how NOT to get blotches all over the leather, their fingers and their clothes.
$50 for good information is a bargain if it's the information you are looking for. Given that bank shots come up a lot in pool someone might want to know how to bank really well especially if they play pool for money.
In every field on the planet the best information costs money to acquire. Be it in the form of magazine subscriptions, purchasing media, time researching and collecting, personal instruction, taking classes, etc.... you are paying for it.
So whining about the price is silly. Whether 50 or 500 or 5000 the value to the buyer is what they can DO with the information. If it's good quality intel then they can do a lot with it. If it's crap then they can't do much with it.
One thing is certain, without it you can't ascertain the value until someone else tries it first. You can whine about the price but as the saying goes then you are someone who knows the price of everything and the value of nothing.