Good price for the over-ear wireless Sennheisers, these ones are noise cancelling, as opposed to the on-ears. I have a pair myself and I absolutely love it. Build quality is better than that of the Bose QC35, but many reviews (my experience included) suggest that the noise cancelling feature is not as good - however the opposite is true of the audio quality, better on the Sennheisers.
I've never dealt with this store before, but most likely would be able to get an Australian Tax invoice for tax return purposes.
I'd still get the QC35's imo. Much more comfortable.