Valuable things are not cheap. That's our view of Comerica Inc.'s purchase of Sterling Bancshares Inc. in Houston, which investors hated
. Yes, Comerica Chairman and CEO Ralph Babb agreed to pay more than twice the value of Sterling's tangible book at a time when most banks are changing hands at little or no premium to book. Yet Comerica now has twice as many branches in Houston and a new toe-hold in San Antonio
, and it can sell treasury and wealth management services to Sterling customers. The deal was good for banking in 2011 in general, by giving healthy players like People's United, Brookline Bancorp, Valley National Bancorp and F.N.B. Corp. permission to look long and pay up, investors be damned.