I'd pass the offer, I just starting a build of a bit newer E350 but as always purchased from Government Surplus. On the surplus sites the high tops go quick for the non-profits and churches. butt.......... if you watch the 15 pass windows you'll get a great deal (hey with the dogs and all, they'll enjoy the view).
Some don't think the same as I might but the feds have oil changing and maintenance down patt with a written program. The BS seller tell you is mostly what you want to hear, guy's in the motor pools tell you what they do.
If this van your looking at is gas it's at it's life for traveling, and I only look for gas.
Step back grab a cold one and wait for the surplus god's, they always come through, I'd say top price for a 60k van under 3k. If this is your 1st van you'll love the road=ness of the vehicle and the cabin area as well. I've enjoyed your travels and hope you enjoy many more.