Best price I have seen for this, usually retails for ~$220 at most stores.
Price beat at Mitre10 to make it $143.64 (model: 16335110)
Definitely the best window vacuum in the market by a margin and a different beast to the entry level WV1 (https://www.cheapies.nz/node/24032)
Notable differences:
Huge battery life: Karcher WV6 currently has the longest battery life, giving you up to 100 minutes on a single charge. The next model below WV5 has a run time of 35 minutes. The WV2 models have a run time of 25 minutes, while the older WV1 has a battery life of 20 minutes.
150ml dirty water capacity compared to 100ml for all other models.
Only 0.1kg heavier than other models (0.8kg vs 0.7kg)
If you're in the market for one, a very good deal in my opinion.
FYI I have the previous model. They are OK for cleaning windows. Good if you have small children and want to give the windows a quick going over every now and again. Still think newspaper and window cleaner produces a better finish though. Good in winter for condensation on the windows, if you don't want to crack them.