The Island Price Change FAQ clearly said that the old tier price would transfer, for all transfers completed before February.
The land store opened at 12:45PM or so. Zee made his post later, around 1:30, saying that transfers would be charged the higher tier.
All those hundreds of people that purchased islands during that period were acting on the information as it was known. I suspect many of them would not have purchased islands, knowing their potential resale value would be so much lower.
So which is it?
A suggestion: Give us a lease! We need to be able to make business plans. Right now the ownership of an island is something that's governed by the TOS, the billing policy, and a patchwork of various blog posts and answers comments.
Give us a lease, a guarantee of rates for a year, a clear contract where both parties can meet with equitable terms... how about a SLA that means something? You know, things most hosting companies offer.
A TOS might be fine and dandy for a game, but SL isn't a game, stop treating it like one. You are a platform for businesses, start acting like one.
This conduct is completely unprofessional.