24/04/17 update
Prices back up for ANZAC day sale.
Previously part of Addicted to Audio Easter stock clearance sale from 5pm 13 April to 9:00am 18 April.
Current deal matches the historic cheapest price for these classic headphones since Store DJ sale last October. Local retail price for HD600 are around $350 and $400+ for HD650.
I've been following the prices on these headphones for about a year now and these prices are about as low as I've seen them.
Do note that it's strongly recommended to pair either of these with an amp (wall powered, not USB) as these headphones' sound quality scales nicely to extra power.
HD600
https://addictedtoaudio.com.au/collections/easter-stock-clea…
HD650
https://addictedtoaudio.com.au/collections/easter-stock-clea…
As a side note I've looked through the rest of AtA's Easter sale catalogue and TBH, these are the only items with an Easter sale discount. Slightly sleazy of them to sneak regular 'discounts' as part of an Easter special catalogue IMO.
Out of interest, why would you suggest not using a USB powered amp with these headphones?