I haven’t been to Sam’s lately (although they are building a Sam’s in Highland Park in an old Dominick’s building now–just dangerously too close for me), but I did find that you can obtain Laphroaig Quarter Cask bottles from Binnys for a cool $47. Laphroaig has even dedicated a section of their website to the spirit:

http://www.laphroaig.com/qc/index.htm