Modern automatic transmissions do not really present any significant disadvantages over manual transmissions. They require relatively little maintainence, mainly draining/replacing the fluid at fairly lengthy intervals, usually 30,000 miles. They don't reduce fuel economy enough to negate their benefits in reduced driver fatigue, particularly in stop-and-go city traffic, where a 5-speed manual gets really old really fast. My first Corolla was a 5-speed, and considering the literally 100% city driving I do, it offered no clear benefit in increased fuel economy. However, due to the very stiff hydraulic clutch, it was quite a pain to be rowing through all those gears allmost continuously.
On the few long trips I make, my '03 Corolla's automatic yields literally the same fuel economy as the 5-speed did. To claim that you could buy your wife diamonds and jewelry with the savings you'd get from the stick over the auto, you'd have to be able to convince her that the diamonds and jewelry you can get from that Cracker Jack box are the real thing!
The choice between auto and stick really comes down to one thing -- personal preference based on a perception that driving a stick is more fun than driving an automatic. If I were driving a true sports car, that had the performance and handling which one would expect in a sports car, then I'd want the stick shift in order to get the whole effect. However, in a daily driving grocery-getter, that kind of driving experience simply doesn't apply. Moreover, women don't generally drive for fun -- they rarely, if ever, take driving seriously at all, as I see by the way most women appear to be more involved in talking on cell phones than engaging in the act of driving. A stick shift would only increase their distraction level, so why take that risk?
I'd say that one would need to be consistently getting a 10% or better fuel economy benefit before the increased driver workload of a stick over an auto could be justified. In my own experience with two Corollas with each type of transmission, that was definitely not the case. There was, for all practical purposes, no decrease in fuel economy, but there was a significant increase in driver convenience. Until the day comes when I can afford to buy a second car simply for it's fun-to-drive characteristics, I'll "stick" to the automatic.