I would recommend used, if for nothing else then to save on the depreciation. I recently purchased a top-end 5th wheel, 5 years old, barely used, for the low $20's. The only downside was you have to be prepared to spend the time to look and be patient - it took me nealry 6 months to find one I liked. Also, new or used, it would help to have a checklist of the things that you absolutely require in a unit, along with things that you like but aren't deal breakers. Finally, research your prices, again new and used, and don't be afraid to walk away if you can't get it for "your" fair price.
Good luck
Ron S