Cathy,
I did my Peking Duck exploration some time ago, so my response is not guaranteed to be accurate or up to date. The duck skin at all three establishments is very good, although the staff can be a bit heavy handed with the scallions and hoisin if you choose to let them roll your pancakes. The pancakes at Seven Wives were the best of the lot. The pancakes at Moon Palace and House of Fortune have more in common with tortillas.
The duck meat course is very good at Seven Wives and Moon Palace (a bit greasy here sometimes). The duck meat at House of Fortune was not as good.
The soup course at Moon Palace was the best of the three, followed by House of Fortune and Seven Wives.
I think I was charged $48 for the duck the last time I was at Moon Palace. They tend to be a bit heavy handed when pricing off menu or market price special items. I don't recall the cost at Seven Wives or House of Fortune, but I am pretty sure it was substantially less.
Regarding the dried scallop soup, Golden Bull on Cermak has a good version, as does Sun Wah Barbeque on Argyle. Sun Wah's soup includes bits of crispy duck. I find the soup benefits greatly from the addition of vinegar (which comes with ginger at Golden Bull).
Hope this helps some.