(FORTUNE Magazine) – Big fancy weddings are back. Altar-bound couples book the Grand Ballroom of New York's Plaza Hotel for receptions 12 months in advance at $50,000 a crack. For $8,800 they take over the ranch house where Dallas is filmed. They rent mansions in New England and a botanical garden in Columbus, Ohio. In 1984, 2,487,000 couples, 16% more than in 1975, were married or remarried. The newlyweds and their families spent $20 billion, an increase of 152% over the decade, or 43% after adjustment for inflation. The money went for everything from rings and flowers to music, limousines, and honeymoon trips. Few weddings are as opulent as the $50,000-plus extravaganza (left) of Wendy Burden, 29, a descendant of railroad tycoon Cornelius Vanderbilt. But the average cost of a wedding and reception has soared beyond $6,000, according to Bride's magazine. Sit-down receptions can cost $150 a guest. Full-length designer wedding dresses go for $10,000 or more. Lavish flower displays, now the rage, run to several thousand dollars. Photography or videotaping adds $800 or more. Such costs help explain a new trend in the marriage business: grooms' families often share in wedding expenses.