Boostmobile.com is currently having a promotion that shaves $10 off the price of eight basic feature phones:
The Samsung Factor flip phone is $39.99 (reg $49.99)
The Motorola Theory QWERTY candybar is $49.99 (reg $59.99)
The Sanyo Mirro flip phone is $49.99 (reg $59.99)
The Motorola i412 iDEN flip phone is $49.99 (reg $59.99)
The Sanyo innuendo QWERTY clamshell (in blue or gray) is $69.99 (reg $79.99)
The Motorola Clutch i475 iDEN candybar is $69.99 (reg $79.99)
Shipping is free on all phones, state sales tax is charged in all states that have a sales tax.
To get the $10 discount enter promo code WINTER10 at checkout. The promotion ends Tuesday Feb 28, 2012 (the promotional banner on boostmobile.com says it ended Feb 20th but Boost has confirmed on Twitter that it's actually good through the 28th).
If you are considering one of the iDEN phones (i412 or i475) keep in mind that iDEN service will be shut off next year.