I too am really interested in a replica robe and saw there was no replies for a bit so i inquired about it to cloakmakers yesterday this was Dinas response, i hope you find this useful:
Hi Frank,
We had found 32 yards of the movie fabric and were waiting on the owner of the stuntman robe to set up a time to come and take measurements when we got a call from Universal. They were interested in having us make robes for Scream 4, but eventually decided to just buy the fabric from us.
We also got a gentle reminder about copyright and license laws. There were no overtures on their part about potentially offering licensing.
If someone ordered robe today, it would be done around mid to end of August. So no, we have not made one yet and will not until someone makes an order. Part of the reason for operating this way is licensing and copyright infringement. We must make 3 significant changes.
Cost will vary with size, and since we have not made one yet, we're estimating. So I'd rather aim a bit high and have the final cost come in at that point or a bit lower.
We're estimating fabric and labor, for the average size male (5'10, 180lbs) and it will change depending on whether you want it with an open front with snaps all the way down (about $365 depending on size), or slip over the head with a closed front (about $300 depending on size). We're figuring it as similar to a Jedi, but the gloves add a bit more complexity.
The three changes would be fabric (similar look with sparkle but heavier), making it to your measurements, and not attaching a mask. We would leave an extra fabric layer inside the hood to attach the mask to so no hair or skin shows.
One interested customer is searching to see if he can find a closer fabric.
Dina