For those of you looking to collect all the Star Wars polybag sets, the Umbarran MHC has been spotted in Ottawa, Canada at Chapters. It was priced at $4.95 Canadian.
Thanks to Brickset member Shaase for the heads up. Much cheaper than the current Ebay prices.
UPDATE: It appears that if you spend $30 on regular priced LEGO products at Chapters, you also get one of these (or a different polybag free.