By Thomas Gryta
Maybe T-Mobile USA Inc. was a big winner in the recently completed government wireless auction after all--with AT&T Inc. picking up the bill.
The record $45 billion in bids pushed up the market value of "mid-band" spectrum, a category that includes the airwaves AT&T turned over to rival T-Mobile in 2012 as part of the breakup fee for their failed merger.
The breakup fee was one of the costliest ever. AT&T took a $4 billion...