Frostgrave Gaming Mat

[Golgotha]

These look interesting too of a similar style http://www.pworkwargames.com/en/30-pdf-mats

Various landscape types available. At any rate your table looks good especially with terrain pieces. They also make PVC mats which cost more but may well be better looking and or more robust and avoid any join lines.

[Paboook]

I own this one: 4x4 G-Mat: Arctic for € 49,00. Not sure if they plan a 3x3 variant as well.



http://www.gamemat.eu/4x4-g-mats.html

[mister c]

Heroic Maps are currently discounting a different winter set each week up to Christmas.  This week its a four map set of Dwarven underground chambers.
http://www.drivethrurpg.com/browse.php?keywords=trostenhal&manufacturers_id=5371&x=0&y=0&author=&artist=&pfrom=&pto=

[Polkovnik]

Heroic Maps currently have a sale on so their Frostgrave (Frost Ruins) mat is currently available for $1.80 for the pdf.
http://www.drivethrurpg.com/product/162799/Heroic-Maps--Terrain-Frost-Ruins?manufacturers_id=5371

[Elbows]

Kraken Games out of Germany has a fantastic one, but I'm not sure how many retailers are carrying them yet (the KS seems to be delivering).



They have a 3'x3', 4'x4' and 6'x4'.  Mousepad material.

[Steelwraith]

I've got these one foot by foot and a half felt pieces with a cobblestone pattern embossed on them, which I got from the local crafts store. At a dollar a piece they're pretty cheap, but I must say that pic above is pretty darned cool.