I have one antique tetsubin that I purchased from Kuraya Antiques in San Francisco. Each time they are expecting a new shipment of items from Japan they often put their current stock of items on sale (Taylor, if you are in the city, its worth stopping in to one of their two locations to take a look around; they only put some of the stock up online) I really appreciate its smaller size, aged but well-kept disposition, and its immaculate pour. I paid $370. It's been well cared for and has a nice layer of maintained rust inside.
In the house I have two tetsubin (one antique/vintage and one new Yamagata style Seiko kettle), two silver kettles (one small, on large), three clay kettles (a Taiwanese unglazed clay kettle and two (one small, one large) glazed clay kettles) and a Bonavita. This little kettle is by far my favorite:
My second tetsubin is a Seiko kettle that I purchased from Yahoo Japan, through Jauce.com, for $200 new (total of $250 with fees and shipping). It came coated in traditional urushi inside and with use a rusty sheen is beginning to peak through the urushi. I appreciate its subdued presence and comparably larger size.