Assigning copyright, acceptable fee?

Hello everyone.. I have an interesting question for you all.

I am a very new web designer in Canada.

I have a client that wishes to own the entire copyright for the website I am currently designing for her (ie have the copyright 'assigned to her as opposed to her being licensed to use my design for her site)

I have done my research.
Canadian copyright law does normally protect my copyright for the design/layout etc. of the site, while still maintaining her copyright to the 'content' of the site.

But it is possible to assign the copyright to my client under Canadian copyright law ( http://www.cipo.ic.gc.ca/eic/site/ci...0090.html#no17 - The link is to the Government of Canada Intellectual property Office FAQ )

My client does have a valid reason for requiring ownership of the copyright for the site design, and I AM willing to grant it to her.

My question is this.. as the assignment of the copyright was outside the original scope of my price quote to her, and I have never encountered this situation before; what would (in your opinion) be an acceptable fee for assigning the copyright to her?

Note: the site has minimal graphics (simple backgrounds for header, footer and buttons) no logos designed by me, basically just the layout and navigation template for her site.