I would think that you wouldn't need a lot of embellishments unless it's a really plain dress. If she has a wedding photo it would be nice to print on fabric and include either in front or in back. You can do a lot with white embroidery thread on seams...not costly! Add some pearls and maybe white silk ribbon (or already made up) roses. I'd be sure to check her wedding colors and any special flowers or colors--if she wants to use color... I can't help on the price, but, good luck.... Frankly, if she were a good friend, I'd ask her how much she's willing to pay. You might want to Google Wedding Dress Quilts and look on Pinterest. Don't worry about the fabric. Lots of crazy quilts include wedding dress bits.