Some people in this thread are saying that people should not post abroad, I do not agree with this as it was the buyer and seller who agreed to mark the customs significantly lower than what the item was worth. If they didnt do this, the customs would only be a problem for the buyer and not the seller. But Im afraid at the buyer marking a $1190 bag down at $200 then it is both the seller and buyers fault, more so the seller because she is the one who has broke the law.
Many times as a buyer I have paid customs fees for my bags coming from different coutries (especially items from the US coming into Europe) and the customs fees are usually high but Iam able to pay them because they arnt too high. I can only Imagine that a $1190 bags customs fees will be just below $400 which is alot unless the buyer has accounted for this allready (which it seems she has not).
IHeartCoach - the only thing I would advise would be that if the buyer can declare the bag at full value (without you getting into trouble/or if they dont need to see an invoice and just send it back) then have the bag sent back to you and refund her (- her postage), that way it would work best for you. Obviously you will have not sold the bag and made a sale but you wont get into trouble and the buyer doesnt have to pay customs fees.
If you do print out a fake invoice then you could get yourself into more trouble because they may check it and may ask for more proof. These days they check everything coming into Europe.
Goodluck