It's cool to see a negative result get published.
I do wonder, though: the group being studied (post-menopausal women) has both had a lifetime of experience in dealing with varying hormone levels, and is old enough that they may well have fairly set habits and heuristics for their 'economic' dealings. From an evo psych perspective you could also argue that they should be past the point in life where certain types of motivations would be useful. I want to see the same experiment done using 17 year old boys :-).