Another vote for shopping Craigslist.

Our first tandem was pretty much wrong in every way. It was a DiamondBack, so not in the same class as the cheepies, but still ...We'd have probably just killed ourselves on one of the cheep cheepies and that would have been that.

We attempted an organized half century, that was brutally cold and windy and basically awful, had trouble getting SAGged out, and by the time the bike fell out of the back of the pick up truck, I was ready to leave it in the street and drive away.

We recovered with a second hand Burley and finally got a CoMotion which we completely love.

NUTSHELL:
Keep your Co-Motion dreams
Start off with something decent--so you can figure out how to ride tandem.
Whatever you ride, make sure it fits both of you!