re: My two cents on mission costs
Beagle 2 Lander. Art conception of lander on Mars.
One of NASA's Mars rovers. Yes, the rovers are much bigger than ESA's lander and even NASA's Sojourner rover and needless to say, more complex... down to the wheels (functional hubcaps!). Two large rovers sent seperately.
The expense is obvious to me. Luck will undoubtedly play a part, technically and scientifically for both program missions.