The answer to your question is Reverse Holo. It is harder to get a Rev Holo of a certain card than it is to get its holo version (or non-holo if it isn't a holo) so it is worth more. I personally don't like Rev Holos as much as I like holos...
Rev Holos of Holo Rares are worth less as their Holo counterparts though. However, they are worth more as any of their rare/uncommon/common counterparts.