Amazon offers Prime members the Panasonic Noise-Canceling Stereo Headphones in Yellow, model no. RP-HC200-Y, for $18.72 with free shipping. (Non-members can spend $35 to qualify for free shipping; otherwise, shipping adds $6.67.) That's the lowest total price we could find by $13. They purport to reduce outside noise by up to 14dB and feature 35mm drivers and a frequency response range of 10Hz to 21kHz.

Orders placed via 2-day shipping by December 22 will arrive in time for Christmas. (This option is free for Prime members, but an extra $11.83 for everyone else.)

Update: The price has increased slightly to $20.11.