Dress Question

Ok, so I am wondering if anyone has any suggestions. I found a dress this week but it is a sample dress, that was donated to the Bridal Garden in the city by a designer, I put the dress on hold for 1 week because I love it, but heres the problem, the dress is a little too big for me and needs to be altered by a seamstress. Does anyone know of a good seamstress who is reasonable in price? The girl at the shop offered to take the dress home and alter it for me for $600 but I don't know how good of a seamstress she is.

Any suggestions? I included two pictures