Would anyone pay a subscription fee of $99 a year to access fixed-price domestic tickets?

[Mattg]

This is where being an educated consumer can come in handy.

If you fly a particular route often enough and have a sense of the prices, you'll know a genuine '50% off' when you see it.

As I said in my post, it's 50% off the fully flexible fare. The airline is very clear about this. The benefit of it is that you can book any flight as long as there is at least one seat left for sale on it, at short notice, at a guaranteed price. Yes, it may well end up cheaper to purchase tickets months in advance, but this is won't work for everyone.