Cafago offers the Wake Up Light Alarm Clock for $24.89. Coupon code "PT1961" drops it to $18.49. With free shipping, that's the lowest price we could find by $4 (although we saw this for about a buck less four days ago.) It features different colors and brightness levels and is powered by batteries, USB charger, or AC adapter.

Note: This item ships from China and may take from two to five weeks to arrive.