It would seem Equifax has estimated $400 million of cash (at least as of June 30) to pay this ransom.
https://www.sec.gov/Archives/edgar/data/33185/000003318517000023/efx10q20170630.htm (page 7)
I think they should bite the bullet and pay, then hire the hackers as consultants to help the company solidify their IT so this doesn't happen again.