The St. Louis business community has been abuzz today about the $65-a-share offer that Inbev is rumored to be preparing for Anheuser-Busch. Much of the attention has focused on that headline number — $65 a share equals $46 billion for all of A-B, which may prove extremely tempting to shareholders.

In St. Louis, though, another number in the original FT Alphaville report should give folks pause: InBev reportedly thinks it can cut costs at A-B by $1.4 billion a year.

Mark Swartzberg, a Stifel Nicolaus analyst, crunched the numbers too, and he agrees that $1.4 billion in cuts would be necessary to make the deal pay off. That’s a huge number, equal to about 35 percent of A-B’s earnings before interest and taxes, he notes in a research note published today. But it’s probably considered achievable by InBev’s bottom-line-focused executives, Swartzberg says:

We believe execution risk achieving such a number is high, but $1.4 bn is approximately $10.70 per wholly-owned AB barrel and would lift AB’s OI (operating income) per barrel to approximately $34 per barrel. That’s an amount in line with InBev’s OI per barrel, which is in the $30s.

Sounds to me like a cost savings of that magnitude would be extremely bad news for the 6,000 or so A-B employees in St. Louis.