The Best Buy Black Friday $29.99 deal on the JBL 12" GX1200 subs is still active and on eBay with free shipping. Although quantities are listed as limited.
These are 300 watt rms subs with a claimed 90dB sensitivity.
I've not heard them and I'm certain they are JBL's bottom tier entry-level sub. But, they might make a good first subwoofer for a teenager or for a low cost garage/shop sound system.