210, wide angle. Christmas present, so I don't know the cost. It apparently came with four packs of film, ten shots in each. I asked for - hinted strongly for - the wide angle version as I thought the regular one would be very small. Also, Fuji seem to be really putting effort into the general Instax concept, so there should be some longevity. Above all, it's great fun to use.
Why: Its instant. Its film. Its available. Cost to shoot is (fairly) reasonable. I'd been wanting one for some time but had just never been compelled strongly enough until I saw Rob's images just after Christmas.
How much and Where from? I got it from Amazon (I had a gift card) for about $65 and free shipping. However, my local big chain photo shop (Samys) has them at about the same price. Film is about $22 for a twin pack (20 images) at Samys, but I got a twin pack from Adorama for about $16 and free shipping.