Strategy is simple. Get free users and then go for Mid-Tier/Enterprise. No startups paying $15/Month stuff. I have seen this with others and it seems to be a working strategy ?
I see where you're coming from - we actually previously had cheaper plans but decided to remove them in favour of a Free plan which we introduced last month. We want people to use the platform, see the value they can get from it and then upgrade when they are ready (and content about the impact their apps are having in their organisation).