At the 5k price point I'd get a Sienna over a Grand Caravan all day every day and twice on Sunday.
Why do you say that? Just curious.
1) I think the Sienna is built to a higher standard than the GC. So as the miles rack up I assume the GC will start to feel old and tired long before the Sienna. And the GC will likely require more repairs, even if it is a few years newer. Case in point, my 12 year old Highlander feels and works like new (granted it only has 180k km).
2) Perception of the average owner. The Sienna was a good bit more expensive when new so people that were buying were buying for the long haul. That means they likely took better care of them. I think a lot of people view the GCs as disposable and rode them hard and put them away yet.
Admittedly they are my own bias' and there are likely exceptions to both points.