You can't buy this one. The Grizzleheim station is an actual place. Go to the back of Northguard across the river, and into a door back there by some standing stones. Inside, you will find the GH crafting station.
By the way, once you get to Dragonspyre, there is another station like it, a physical place up in the Dragon's Roost area. Some DS recipes require that station only.
its official name is "hall of the ice forge", not that it really matters, just didn't want you to get confused. it's located in northguard, across the river and behind the waterfall, near mirkholm keep.