Well unless you really do want to carry more than 4 passengers I would get an estate car instead for load lugging. The fuel economy/handling suffers with an MPV due to the height.
I bought a car from an auction recently, my 3rd car purchased from auctions over the years. I saw some people carriers going cheap there and in very good condition.
�4000 will get you a '98/'99 galaxy diesel. They are magnificent vehicles ( sharan and seat alhambra same ). I have had several Galaxys and I love them to bits.
if you have small children then a galaxy, alhambra or 806 will have enough head room. if you have older children or occasional adults in the back then there is not enough headroom and seems cramped. I would recommend a voyager too, loads of room and comfortable ride, more car then mini bus and good specs. loads of boot space even if its not the grand version.