Fry's offers a single Polk Audio RTI 12 Floor-Standing Speaker in Black for $299.99 with free shipping. (Price shown in-cart.) That's the lowest total price we could find by $349. This speaker features three 7" woofers, two 5-1/4" midranges, and one 1" silk dome tweeter; it handles 50 to 500 watts of power.
Note: If you're looking for a pair (or more), you'll need to place individual orders or choose in-store pickup.
Best Buy offers the Polk Audio 100-watt 10" Powered Subwoofer in Black, model no. PSW110, for $124.99 with free shipping. That's tied with our mention from a few days ago and the lowest total price we could find by $57. It features a 100-watt RMS (200-watt peak) amplifier, 10" driver, adjustable 60Hz to 160Hz low-pass crossover, and frequency response of 32Hz to 250Hz.
Best Buy offers the Polk Audio 10" Active Subwoofer, model no. PSW108, for $99.99 with free shipping. That's the lowest total price we could find by $20. It features 35 to 200Hz frequency response, 100 watt peak power handling, and a Klippel distortion analyzer.