I don't know how much they cost (I have an off the shelf carbon bike) but there was a custom carbon builder in Bicycling Magazine. Crumpton Cycles out of Texas, I think it will set you back way more than $3,000. I think any completely custom bike will set you back more than $3,000 for the frame.
I personally have my eye on a Lynskey custom Ti Bike, I do not desire another carbon bike. If she is looking for comfort Ti or Steel would fit the bill as well and you would be surprised how a bike that fits can be fast because it works with you.
Wonderful gift but I think you should let her pick what she wants. Orbeas are sexy bikes but if they don't fit they are worthless IMHO.
Amanda
2011 Specialized Epic Comp 29er | Specialized Phenom | "Marie Laveau"
2007 Cannondale Synapse Carbon Road | Selle Italia Lady Gel Flow | "Miranda"
You don't have to be great to get started, but you do have to get started to be great. -Lee J. Colan