Dress too short

So, I got my dress last week- I ordered it from a salon out of state. I try it on and it stops just at my feet- when I'm barefoot! It turns out when I tried the dress on at the salon, some of the pick-ups had fallen on the sample and it appeared much longer than it actually is.
Now, I'm very tall so I don't mind wearing a small heal or even flats- but even if I did that you would see the entire shoe.

So, I contact the designer directly to ask them for tips that I can give to the seamstress to have them lengthen the dress. They were very nice and offered to lengthen the dress for $100. The only problem is that they are in California so I would have to ship the dress (and insure it) and then wait for it to be returned.
He said as an alternative, they could send me the fabric to have the seamstress do it herself.

So, what do you think I should do- send it to the designer and have it done perfect or have the seamstress do it along with the other alterations and save time and money!

Here's a pic of the dress: