Cats across the border

Has anyone had experience with bringing or selling a cat across the Canadian/US border? I am purchasing a cat from the states, but I am going there to pick her up. I'll fly back to Seattle and drive across the border with her, and they may not even ask me for her information. If they do however, I read online that I need proof of rabies vax plus a certificate of health from her local vet.

I know if I produce a bill of sale I'll have to pay duty on the purchase price, which can be steep as she will be more than $1,000.

The breeder has suggested that she provide a letter stating that the cat is co-owned by herself and me, which is partly true as we are working out a deal on kittens back.

Is it completely unethical to produce a bill of sale or such stating that the cat was given to me? I just want to avoid a huge duty charge at the border.

I'm no real help. Has this breeder ever sent another cat to Canada? I can post your question on our Ocicat board and see what the breeders have done. Just pm me with a yes or no and I'll cut/paste your question to them.

To clarify, I am not worried about doing this, just wanted to see if others have had similar experiences. If it comes down to it, I'll just pay the full customs and duty.

Veeshan is from Canada but I did not have to worry about a bill of sale. We did have a health certifcate but it was never asked to be seen. Veeshan was to young at the time for rabies so we didn't have to worry about that either.

I shipped a kitten to California and all I had to do was pay for the airfare and the vet check, vaccinations and proof from the vet that she was seen and up to date with all shots. She was sent as a "gift" to a friend.

I have placed several kittens in Canada. We did a contract with a bill of sale and if your cat is intact, you will have to pay customs. As to a bill of sale, an amount you need to come up with is up to you. If you are getting a kitten back deal, then thats not what you are paying now which to me is what you are paying for the cat.
Thanks
Daisy