The ToysRUs.ca web site has the Siege Battlemasters at clearance pricing now, they are listed at $5.98.
http://www.toysrus.ca/product/index....ctId=159646056
http://www.toysrus.ca/product/index....ctId=159646046
http://www.toysrus.ca/product/index....ctId=159646006
Maybe they might not carry the Battlemasters after Wave 1, like when they stopped selling the Titan Masters after about Wave 2 I recall.