I don't know how much importance the B1G attaches to an applicant's fiscal resources, but if it does, I don't think it would consider a billion-dollar endowment to be very impressive. That's chump-change nowadays. A quick search on Wikipedia reveals that most B1G members have pretty sizeable endowments. OSU, for example, is at $7.9 billion, Northwestern at $14.3 billion, newcomer Washington at $6.6 billion, and so on. Michigan has a whopping $19.2 billion endowment. Rutgers, which is treated rather dismissively in the Boneyard, has an endowment of more than $2 billion. The University of Utah may be an aspiring B1G member, but its endowment is only $1.64 billion. Even so, that's about 2.5 times the size of UConn's.
The B1G is also a research powerhouse, and UConn doesn't compare very favorably in terms of research activity. UConn has a very long way to go.