I got my first bag (and currently only one!) from ebay and I really don't regret it one bit. I know it's authentic and I simply would have had to wait for a very long time if I waited to go Boutique for the first time. I'm impatient-wasn't willing to wait!
Dh bought this one for me off of ebay for my birthday and then he told me I could get another one for my birthday as well because I complained that this one was a bit small for me. Recently, I did make a trip to the boutique to look around and I found the next purchase (hopefully!)-a large Soho flap but I'm torn whether to get brown or black. I showed dh a picture of it online this morning and he loves it-he really likes it in brown. I'm hoping I can get it soon!
If you possibly can, I'd recommend going to boutique for your first-but if it means waiting months or even years, just go for it however you can! I still feel like this first bag will always be special to me just because dh got it for me and well, it was my FIRST!
There are so many cool stories in this thread, I love reading them!