Both Amazon and Best Buy have the Sony MDR1000X/B on sale for $298 and $299.99, respectively. Lowest price I've seen on these sites (MSRP is $399 and previous low price I saw was around $330). There are some concerns about the headband durability, but at this price I might just bite.
Best Buy: https://www.bestbuy.com/site/sony...Id=5581069
Note: If you don't want to pay tax, there are other buying options on Amazon that are tax-free (back-ordered for a few days; sold by reputable sellers and fulfilled by Amazon).