My only experience with sending something back for repair was approx. 3 years ago. I had no problem. As a matter of fact, I was surprised how well it actually went. I bought a large tote at the outlet. I don't remember exactly what I paid for it, but I know I got a great deal. I want to say I paid just a little over $100.00. I took it with me on vacation. I hung it on the handle of my suitcase like an idiot, when going thru the airport. I did not realize it was dragging on the ground. It TOTALLY destroyed the bottom almost making a hole in it. OMG it was my favorite bag I was so upset. I took it into my local retail store and asked it they thought it could be repaired. I fully admitted what had happened that it was totally my fault and had no problem paying what ever it would be to repair it. If it was even repairable. They told me it would be a $20.00 service charge for S&H to send it back to the factory to see if anything could even be done. I paid the fee and was told I would have an answer within 2 weeks. Well, less than a week later I got a letter from Coach saying that my bag was too damaged for them to repair it and they did not have a new one to replace it with. I needed to sign the letter and send it back to them and they would send me the value of the purse in the form of a gift card. I was totally expecting what I paid for it. I could not believe it when I got a gift card for close to $400.00.
Other then that time, I have never needed send any of my 20+ purses in for repair. I thought that was standard of how they handled repairs that if they could not repair the bag and they still had them in stock they would send you a new one and if not they would send you a gift card for the value of the item that was being repaired so you could get something else. Things might have changed since then.
I thought it cost 20 no matter if you send it in yourself or go to the boutique. If I send it in its easier for me to go thru a boutique b/c I live in Canada.