At 30 feet on an E-350, I would defiantly drive it and check the handling. There is a good chance it has a V-10. Read about the spark plug problems with the V-10 of that era, spiting plugs out.
I have a 1998 Four Winds 23 foot with a V-10 with 37k on it. I knew about the V-10 when I bought it. I'v put 3K into it to fix handling, and a bunch of preventive maintenance work: including new shocks, serpentine belt, fuel filter, tie rod ends, and dripping pinion seal plus some other stuff. Not saying don't get it, just saying there is a lot under the cover that is not obvious. Everything else was in excellent shape so I bought it last September. I was at the front of the line, there were people right behind me after the same unit, and glad I bought it, lots of fun.
1998 Four Winds 5000 Rigby, ID