I am looking also. At first I thought I could hopefully find a good use 5th wheel in the lower $30k range. For the pass two plus years I have been trying to educate myself on tow vehicles and RV's . First and most important trying to find out what I can "safety" tow. Finally found the answer on this web site RVSEF.com or RUSEF http://www.rvsafety.com/rv-education/matching-trucks-to-trailers . You have a newer truck and can tow a lot more than my old 99 Dodge 3/4 diesel.
I am now looking a both new and used RV's. For new RV in the $50k to $60K range look a Northwood/ Arctic Fox RV. Heard nothing but good things about their RVs. I thought at fist a 30 foot 27-5T model to hopefully get into most state camp grounds. My wife and I just look a Arctic Fox 29-5T that is 33'X11" long. She likes the bigger 29-5T unit. Had a new 29-5T unit price out for $54,775.
For used units if you want a RV around the 34,36 or more long size look at Dream Suits / DRV. They have Disc brakes and other high end features like 3-1/2" walls. I have seen 2007 to 2012 year used units in the mid 40K's to 60K range plus. These DRV units are truly full time designed units.
For Deamers; check out this very high end RV brand I just found, LUXE.
https://augusta-rv.com/luxe/ Could possibly be the highest end brand 5th wheel made. New ones are in the price range of $135000, plus.
I am still dreaming for finding a good used unit, but most private seller want a lot for them, say 2012 to 2016 Arctic Fox units $42,000 to $49.000. You can get a new unit for about $4,000 to $7,000 dollars more.
Good luck and wish me luck also.
Chuck