Cheap e-book readers at a glance

Five cheap e-readers with monochrome screens and Wi-Fi:

Ÿ Barnes & Noble Nook — $139, 7.5 oz. Touch screen. Value score: 9 out of 10.

Ÿ Kobo eReader Touch Edition — $130, 7.1 oz. Touch screen. 8 out of 10.

Ÿ Kindle with Special Offers 3G — $164, 8.7 oz. Has ads in screen saver and top menu, cellular wireless connection. 6 out of 10.

Ÿ Kindle with Special Offers — $114, 8.5 oz. Has ads in screen saver and top menu. Along with 3G, largest in test. 4 out of 10.

Ÿ Aluratek Libre Air — $130, 6 oz. Only one in test with reflective LCD rather than e-ink. Smaller screen than the rest, shorter battery life. 2 out of 10.