I bought a set of these as offered here recently.
I simply paid the buy it now price ( a little less than this one) as I thought it fair. The seller, Ron Boi, who I believe is of RRB cycles, asked if I wanted more. From that I gather he has a few sets of what I consider to be a hard to get and desirable item. Consider that you get a demultiplicitor (sp) to boot.
I am getting a bike from Canada soon and it was shipped by Purolator Courier. As I looked at their web site they seem well equipped to handle customs without a seperate charge and they also handle very large packages. A tandem would easily fit their size limits. so apperently it is easier to ship a tandem back and forth to Canada than within the US!
Joe