Probably not a bad deal for a 24 year old van. Personally, I'm not a fan of the 'conversion vans' - look pretty but don't make for a good fit for full-timing it.
Make sure you crawl under the van and check out the metal under those running boards. The running boards can hide some awful rust.
Most people who pay for the conversion vans end up gutting them because a) the plastic trim interior takes up up to 6" of valuable space on each side the van, b) that fold down 'bed' is notorious for being absolutely totally uncomfortable and c) the interior and extra seating isn't needed. If you're going to do that, take that in to consideration when you try to talk the current owner down in price.
If you're not experienced at buying, make sure you take someone along who is and/or a mechanic to check it out and tell you what it needs to make it roadworthy.
Check the dates on the tires - a lot of the vans that haven't been driven extensively have outdated tires. They should be no more than 5 years old to be roadworthy, no matter how much tread is left on them.
Bonus points for things like brake lines and rubber (hoses and belts etc) already having been replaced. If they haven't been it's almost a sure bet they'll need it really soon.
