You might want to check places like David's Bridal,,they have $99.00 dress sales quite often,,or try some of your local higher end department stores,,if you take a look as the seasons are changing sometimes you can get great deals.
You can also look into maybe having the dresses made buy a dress maker,,I did this at a friends wedding and it was quite a bit cheaper because we bought the material oursleves.
You might also have your MOH do some research to help save you from pulling all your hair trying to research everything,,have her show you a few styles she likes,,just give her some guidlines that you would like her to follow??
You're probably not going to please everyone,,but you know,,when all is said and done,,everyone will have had a great time,,and always remember your wedding,,*smiles*.