The site we use the most for finding cheap inter-europe flights is http://www.whichbudget.com Yes, there are often flights advertised for 1 euro or less - they usually amount to around 25 euro with taxes and fees. The cost of getting to or from the low-cost airline airports in some cities - especially London -adds more than the cost of the cheap flight quite often! Takes a lot of time too. The easiest scenario is flying a major airline into a major airport, and flying onwards on a cheap airline out of the same airport. We've found Amsterdam's Schipol airport to be the best for this. We used this method in December, flying United from Washington-Dulles airport to Amsterdam, then a cheap flight with Meridiana got us to our destination, Florence. It saved us hundreds of dollars.

Happy travels, Anne in northern Virginia