Grey-market is putting too positive a spin on it.
Beware these options - none of them are guaranteed in any way shape or form, and the channels that most stand to lose from these (subscription ones, like Nova) actively try to curtail (read: shut down) the use of these streams. The hardware that is used is often very out of date, I've seen multiple boxes that were supplied by "Mitso's friend Saki in Germany who knows what he's doing." Only to open them up and discover that they were state of the art back in 2001 and required the use of a DVI-HDMI adapter.
On the plus side, if it's worth it to you to spend a hundred bucks on a few months' worth of shitty Greek TV, then give it a shot. You might luck out and have it last for a while.
Amorgiggles, I like how your link's product title says "Quad Core," "4K," and "5G" when it is none of those.