We regularly raise prices as Ghost(Pro) matures as a platform and a product - and anyone who signed up early and maintained an active subscription is always grandfathered on early adopter pricing for life.
If you started a trial in the last two weeks and the prices changed on you mid-way through that time (as it sounds like the case is here) then just reach out on support@ghost.org and we’ll be more than happy to honour the old pricing for you :)
Edit: Also, you’re absolutely right that the comparison page is out of date, I’ll make sure that gets fixed up