All daysailer I, II III and IV are 16 foot 9 inches, but there are some smaller O'day boats in the 14 to 16 foot range. Try the O'day website for samples. I think the names are Javelin and Spray.
http://home.att.net/~oday/index.htm
Prices vary greatly factored by age, condition, rigging and equipment upgrades, trailer and even location. I have seen prices from under $1000 to $3000+ used. Check the by and sell on the home page of this forum for sample prices. I acquired mine by swapping a cedarstrip canoe and a couple of paddles.