It strikes me as either absurdly high or absurdly low.

Why high? Because $7/month buys you more than one DigitalOcean droplet, which equates to hosting a static site for you. Drop in a static site generator or just a single HTML page and you're right up to the same point as you are with this: all the hard work is generating the questions and writing the answers. If you aren't a for-profit business, this is way too much money. If you're a scrounging-for-pennies startup, you already have a website -- don't spend extra on this.

Why is the price low? Because anyone who is making money off their product or service can easily afford to hand you $84 a year to make their FAQ pretty and easy to edit. $7 isn't actually enough to make them take you seriously. Does it handle user management for a hundred users? Does it integrate with a single-sign-on system? Can you privilege users to edit certain topics and not others?

Hi, Jan here from SlimFAQ. We actually built this for ourselves initially to solve the problem of allowing non-tech support staff to build and maintain FAQ's for our other products and have it nicely integrated with Intercom. Sure, if you are a developer you could maintain a static FAQ and pay nothing, but for the price of a couple of beers you get a super easy to use CMS and a lot of people seem to want this (us included).