These Headphones have been drastically marked down. I believe they were $129.95-134.95 at Costco, now only $79.95.
Sony's RRP for this set is $229!
Bing lee also has them marked down to $99.95:
https://www.binglee.com.au/sony-mdrhw300k-home-wireless-hi-f…
Sony MDR-HW300K Wireless Hi-Fi Headphones
*40mm dynamic driver for high quality audio
*Passive Listening Mode
*High energy neodymium magnets deliver powerful sound reproduction
*Slider headphone design
*100 Feet (30m) Effective Range
*Pressure-relieving luxury ear cushions for extended comfort
*Compact Uncompressed 2.4 GHz Signal Transmitter
*Built-In Lithium-Ion Rechargeable Battery
*Up to 10hrs of playback enjoyment
Was $67 in previous sales.