It could be that Smartcruiser has group rates?
My story is that I have a current booking with X - cc class - booked solo and the price I am paying is less than the twin share rate with X on their website. So as a solo I am sailing for less than you and your wife would each pay - go figure. BTW I am not complaining
and this is not the first time I have managed to achieve this.
It pays to shop around.