There is no justification for the price tag, and there needn't be. They won't sell a lot of these, but they already know who will buy them.
The same people who buy everything they put out.
So go tap the same well. Charge whatever you want. $100? $150? Doesn't matter. To the buyers the price tag is largely irrelevant. We all know that every song will be available legally or illegally, so they are selling bookshelf appeal. We've fallen for it before and will do so again in many cases.