The Metropolitan Opera raised $3.8 million at its gala last night, a more than $1 million increase over last year's event. The boost is due mainly to the hundreds more tickets sold for the post-performance supper (which cost up to $5,000). The high-flying crowd had to walk to a tent for that supper instead of stepping up on to the Grand Tier, but they still had time to enjoy the opera house's meeting ground for patrons: it was the site of the cocktail parties before the performance started and during intermission -- when it was named the Mercedes Bass Grand Tier.