Thumb Score: +37

Woot! [woot.com] has Sennheiser HD 600 Open-Back Dynamic Wired Headphones for $229.95.
Shipping is free for Amazon Prime Members (must login with your Amazon account and select a shipping address in order for Woot to apply free shipping) or is otherwise $6 per order.

Price:
$270 lower (54% savings) than the reference price of $499.95