What I _would _do is pay a flat fee to subscribe to several publications.
That's the only path: to give people more value than they expect for less money than they expect.
It could be multi-tiered: the more publications you subscribe to, the less each costs. So like there's the $19 plan, the $29 plan, and so on. Some tiers are even ad-free.
You'd also need to nurture all of these subscribers with a sense of community, public radio style.
This is more likely to emerge in the newsletter space than in the traditional new space. Innovator's dilemma.