Of course, it doesn't guarantee the immense popularity of the card, so it's hard to say in what direction that price will go
Add to this the fact that it was a card given away at a convention not specializing in TCGs, and few have kept it in perfect condition (potential CCC 10)
Others, like the evolution of design sensibilities over time, however, are a much more subtle process
It pulls a whole lot of work for a simple common.
Simple, effective, versatile removal for Sapphire
If the creature stops being a creature after the ability has resolved, it will also stop being a Phyrexian until it becomes a creature again, if applicable