Money and Other Women...?

There seem to be only two triggers to get my wife to pay attention to me:  spending money, and the interest of other women in me.
She shows interest if I buy something really expensive:  a new car, a new TV, put down money for vacation, etc.  It doesn't have to be money spent on her; the most attention I have gotten from her in years was when I took her with me to buy some new suits.  Obviously, I can't use this angle to resolve our problems.  If I buy expensive stuff all the time, we'll go broke.
She will also pay attention if another woman seems interested in me.  Nothing quite gets her head turned like another chick prowling around.  I suppose there are times this could be useful.  Most of her friends have no interest in me, but there is one that can always be counted on to keep things interesting.  If I was like many men, I would have just boinked the heck out of her a year ago. However, I'm not that guy, and I don't want to be.
This friend of hers is super kind to me.  There are many times when the four of us (two wives and two husbands) are out, and I will ask my wife to do something ("Please pass the napkins, dear, would you?") and her friend is the one that complies.  When we go somewhere, she doesn't walk with her husband, or sit with him; she always seems to be sitting next to me.  Sometimes it is a little awkward.  She stands so close to me that I can feel her arm hair; she has really hairy arms for a woman.  Despite her arms, she is actually kind of pretty, and has a better figure than my own wife.  She's not the belle of the ball, but she does motivate the missus to act better.  I used to think that I should offer her friend money just to come over to our house every few days.
Sadly, neither of these ideas really solve the core problem.  My wife should be interested in me when I'm not plunking down a big roll of dough or getting hit on by a check-out girl.  Those occasions do not come around often enough to make a difference.