We once purchased a 2 year old 2001 Cardinal that was excellent up until we traded it in on our current 2015 Cedar Creek Silverback. We intended to purchase a 3 year old used unit, but found that there was water damage and ended up with a new model.
We looked a the used market prior to the time we got our new unit and found that you really need to be picky about what you buy. Keep to your specific wants & wishes because you will find the one you're looking for.
Not sure where you live, but we've found while in Florida for the winters that there are some good deals down there with used units. Many folks just end up selling their 5vers because they don't own or want to buy a new tow vehicle or someone passed away, whatever.
For the $30-$40K range you will find yourself a nearly new 5ver, likely 2-3 years old.