Charlemagne OK but Louis the Pious?

Unusually, as Amazon suggestions go, this one tempted me. Maybe because Louis and Pious are almost, but not quite, a visual rhyme. And then I saw the price.

Greetings from Amazon.co.uk,

As someone who has purchased or rated On Sparta (Penguin Classics) by Plutarch or other books in the Historical > BCE-500 AD category, you might like to know that Charlemagne and Louis the Pious: Lives by Einhard, Notker, Ermoldus, Thegan, and the Astronomer will be released on 15 December 2009. You can pre-order yours for just £67.93 by following the link below.

Charlemagne and Louis the Pious: Lives by Einhard, Notker, Ermoldus, Thegan, and the Astronomer Thomas F.X. Noble RRP: £71.50 Price: £67.93 You Save: £3.57 (5%) Release Date: 15 December 2009