For the 6 months of 2010 ending Sep. 30, Ryanair posted total operating expenses of € 1,666,200,000.
They claim to do 1500+ flights a day ~ 273,000+ flights / half year.
So about € 6103 / flight.... give or take.
http://www.ryanair.com/doc/investor/...2_2011_doc.pdf
Disclaimer: Me knows nothing!