Amazon offers a pair of Polk Audio Atrium 4 Indoor/Outdoor Speakers in Black for $99.99 with free shipping. Outside of the mention below, that's the lowest total price we could find by $20, although we saw them for $28 less in October. It features a 4.5" woofer, 75Hz to 25kHz frequency response, and 0.75" tweeter.
Orders placed by December 19 are guaranteed to arrive by Christmas.
A close price: Newegg offers a pair in White for $99.99 plus $1.99 for shipping.