Thirteen
Huh. I'd say the opposite 7/Cups, according to Thoth, is delusion but also desire to experience the unknown to escape plain reality ("I never got to have the super-hot girl and slick car...I want to experience that!") And cup cards aren't just about going into dreamland. They're often about coming out of it. In fact (again, according to the Thoth deck), the 7/Cups itself can lead to "sobering" up. The person comes to realize that the dream was a delusion and by exploring it, returns to reality and is happier with that reality. That sounds like the 7-year-itch to me. Wandering off to experience something unknown with the delusion that it will bring happiness, only to "sober up."Cups are unpredictable dreamers from the "get-go" who never give up the dream, and Pentacles are earthy, predictable and practical by nature, but not immune to getting the 7-year itch.
7/Pents, OTOH, has always seemed to me a card that speaks of something that seemed absolutely possible, not a dalliance or dream or a fling. Not an itch to be scratched. It's something the person really, truly wants, really is working towards. Also something everyone might well think likely to happen (not shake their heads and say, "He'll get over it...")...which is why it's failure is so devastating. Like a phantom pregnancy or a miscarriage. The disruptive aspect of the card is in the expectation of it happening in the now. "Not yet" the card says. But it also says "eventually." The chance to have the real thing is possible.