I found that booking through sites like Expedia are much cheaper then booking through a T.A. or the hotel directly.
Generally speaking this not true for Canadian brides who's all inclusive vacations are very different than US as ours are built by your operators and include flight, accommodation and transfers. Prices are normally the lowest as soon as they are released by your operators and then go up as travel dates approach. Then 90 days out they start to lower their prices to fill the plane since it's a charter and it flies regardless of whether it's full or has 10 people aboard. Great for getting last minute rooms for vacations... But not to great for weddings!