I have built 3 KHSD 12 foot (stretched to 16 foot) trimarans. Cost about $3 using a Hobie 14 rig and rudders with Sunfish daggerboard. http://www.multihulldesigns.com/stock/daysailer.html
these boats are not ment to be an alternative to beach cats. "Driving" position is seated in the center hull with foot steering and all controls within reach. I am trying to develop a sail boat for disabled sailors and elderly folks and building and sailing these three boats has been very enlightening.