Let me preface by saying I've only ever bought two things for FP at the Boutique.
I normally only buy from the boutique whenever I get the 25% PCE coupons and I really want the items I buy. That said, I then wait and never use what I bought until I make sure it's not going to the outlet first. I've found that 80% of what I bought at the boutique does end up at the outlet, so I do a lot of re-buying the items at the outlet, and then returning the earlier boutique purchase (also to the outlet). The SAs at my outlet just LOVE {heavy sarcasm} seeing me walk in the door w/ my bag of returns!