This website has a classified section
there is http://www.thebeachcats.com/classifieds/index.php
craigslist, ebay, peoples back yards

there is a hobie forum (hobie.com) that is a good place to look

my friend just sent out a notice to a Mystere's group on yahoo and got a sweet deal on a 6.0.. and was driven down from michagain to him.. maybe you could get lucky too with an email to the tiger groups online