Based on this survey of attorney fees between 2010 and 2011, it could be anywhere between 510 hours (roughly, in California), to 900 hours (roughly, in the "West"), depending on years of practice and specialty.
edit: that's strictly hourly rates. Some (most?) attorneys will charge you for gas/transportation to and from the courthouse and their office, paper/toner costs from xerox machines, etc, which can add up fairly quickly, especially on a large case like one against Lodsys.
http://www.nclc.org/images/pdf/litigation/fee-survey-report-...
edit: that's strictly hourly rates. Some (most?) attorneys will charge you for gas/transportation to and from the courthouse and their office, paper/toner costs from xerox machines, etc, which can add up fairly quickly, especially on a large case like one against Lodsys.
also, IANAL.