Not cheap, but helps with 10% off code. I dont think they have sales often. Good time to get replacement filter's if you need them. Most of those with free postage.
If you do get a purifier I suggest you buy a few prefilters. The main filters last alot longer, but they suggest the prefilters last about 3 to 6months. Really depends on your air quality. I haven't replaced mine for about 9half months.
Australian designed and manufactured.
We borrowed an older version of the E7 when living in an apartment that was constantly getting dirt and dust from a nearby construction site. The difference in accumulation on surfaces (chest of drawers) was really noticeable when we had it. i.e. from 'didn't I just dust this the other day' to 'barely needs a wipe down'.
Also remember looking at these during the bushfires in Sydney last year, they had ramped up production and still had long delivery times.