Hi Paul,
It will probably be cheaper if you can find someone on the forum with room to spare in their container, although a lot will depend on where the container is heading and where you need your stuff. We were quoted about ?1,200 for a part load of stuff that wouldn't fit into our 20' container. We ended up leaving things behind because they weren't valuable enough to justify the extra cost.
If you decide to ship a part-container load, the shippers won't move your stuff until they have filled the rest of the container. It could take days, weeks or months (but hopefully not years

) before your stuff leaves the depot, let alone lands in NZ.
Anyone else know what sort of rigmarole you have to go through to bring a jet-ski into NZ? It's not a road vehicle (
note to self - duh!?!) so I'm sure you won't have to worry about the LTNZ/WOF/Rego/Statement of Compliance hurdles, but the threat of Didymo will be enough to excite the MAF-Man..........