Honda and Toyota will hold their value better and have a better reliability/safety track record (for the most part). I know many people with previous gen Odys and Siennas and, in general, the Sienna owners (of that generation, 2005-2010) have significantly less, overall, complaints.
The 2006-2010 Odys have a useless 8th seat, if you go with an 8 passenger. You may or may not ever need to use that 8th seat, so that may or may not matter to you. There are 2 complete sets of LATCH in the captain's chairs, 1 complete set in the 3rd row, and and 2 "extra" top tether anchors (outboard). I know a lot of people who have had a LOT of transmission issues in these model years. 2005 Ody's 3rd row is 1 set of complete LATCH; no "extra" TTAs. 40 lb vehicle stated LATCH weight limit.
The 2004/5-2010 Siennas have a child friendly 8th seat, equipped with a full set of LATCH. Each captain's chair has LATCH as well and there's 2 complete sets in the 3rd row. Many people have had misc. complaints with MY 2004, but I have a friend who abused hers and drove it into the ground and it still held up like a champ (it needed repairs, obviously, but nothing major). Defers to child seat manufacturer for LATCH weight limit.
The redesigned Chrysler T&C/Dodge GC (2008-2010) would fall into your price range and would likely have low miles, possibly under 25K, depending on the trim. But, the MPG is terrible (I averaged 13-14 city MPG in my '09) and it doesn't handle especially well...and it won't hold its value. If this is a vehicle you'd want to keep long-term, and to accomodate growing kids, I can't say I'd recommend it. The 3rd row is not child (I was nowhere near 5-stepping) or booster seat (we had SERIOUS booster seat drama) friendly and due to the dramatic slope, it makes many FFing seats a nightmare to install. There's LATCH in seach captains chair and 1 off center set in the 3rd row. No "extra" TTAs, but there is a retrofit part. The shoudler belts are set crazy far-forward. The center seatbelt in the 3rd row is an ELR and ridiculously constructed, so it's pretty much impossible to use for installations or boosters (not entirely impossible, but pretty darn close). Lots of brake issues and various leaks...several airbag recalls, blahblahblah. The floor compartments where the seats would go in stow n go mode are awesome for *stuff* (projectiles, bags, whatever), though. And the Radian installs RFing in the captains chair like a dream. I think they were made for eachother. But those are the only 2 "pros" I can pull from that vehicle. 48 lb vehicle stated LATCH weight limit.