Winnebago makes good motorhomes in general.
Ask to see the maintenance history log. They should have a record of all services performed on the motorhome. Every oil change, any repairs, it should all be there. If not, you have to assume manufacturers recommended maintenance has not been performed and perhaps the rig is running on original oil (shudder to think of that).
Look at the DOT datecode on the tires. Anything more then 5 years old are candidates to be replaced (join FMCA & buy Michelin through their fleet discount but you're still looking at two thousand-ish dollars for a complete set.
Make sure EVERY thing works. Does the plumbing hold pressure? Does the generator start easily and run smoothly? Do the leveling jacks work properly?
Does the seller have clear title to the vehicle or could there be a lien on the motorhome that you do not know about?
Hope this helps.. good luck to you!
Alfred
2005 Sightseer with Workhorse, ReadyBrute Elite towing 2003 Honda CRV
Map below shows states where we actually camped.....