I bought a lot of Burberry clothing last month in Paris and I found that with the tourist discount cards (10% off) plus the VAT rebate, I was able to get these items for less than in the US. This would be at Printemps (the large Parisian department store) as Galleries Lafayette did not extend the 10% discount to their better designer brands (like Burberry) while Printemps did. Example: I bought a Burberry suit which retails for 1200 in the US and it ended up being about 970 US after the tourist discount and VAT refund.
Word of advice: Even though it's a pain and you'll wait in line, get your VAT refund at the store the day of your purchases. I did the refund by credit card and even though it saves time on the front end, you won't get the credit back to your card for over a month and when you do, you'll see that the exchange rate is less than what you'd get if you would take the refund in cash at the store. Depending on how much you buy, it may be worth waiting in line with loud, obnoxious tourists.