Most pay hostings are around 4-5 a month, which is 50-60 a year. Below that there is free hosting which is 0 a year. That leaves a big step between 0 and 50 a year. Free hosting is inadequate for many, but $50 worth of services may more than they need.
What some people may want is a little better than free, cheap hosting. Say if you just want perl, python, sql, and a host that isn't sketchy or will dissappear later, but you don't need 12gb and 300 emails.
A $5, $10, $20 a year plan would fill the gap between free and $50.
Maybe a free, but extremely limited account, and then you could buy upgrades like a chunk of disk space, more bandwidth, cpu etc... for a small fee.
Maybe an "almost free" plan with $2 signup fee.
No one does this, so there's probably a reason for it.