That is alot of money that would need to be offset, there would have to be a pretty good analysis of what a new basketball TV contract would bring for the A-10 with the addition of the Big East bball schools.
I don't think that the BE schools would be interested in joining the A-10. Why wouldn't the 7 of them just cherry-pick the best schools out of the A-10? Heck, there are some schools in the A-10 that the upper tier teams would rather not have (Fordham, Duquesne, St. Bonaventure).
I don't think Villanova would join a league with St. Joe's/LaSalle or that St. John's would join a league with Fordham or Georgetwon with GW or Providence with URI.
If you had a 10-team league, everyone would get a bigger share of the NCAA Tourney and TV money.