I am wondering the same thing. I bought my dress at The Bridal House in Edmonton and I am waiting for my dress to arrive hopefully late Sept they said. So I am going to see what they quote me for alterations and if it's too much then I will probably shop around. Thing is I don't know of any in Edmonton and not from there. So to google that information will just be like taking a chance and hoping for the best.
If you find out anything let me know