With stocks, it just really varies what they are willing to show, either out on display or personally to each client. Since your main concern is savings, I suggest for you to repeatedly visit both boutiques persistently throughout the duration of your stay. If you see it and you want it, buy immediately as chances are, someone is waiting for you to refuse the item so they can purchase it for themselves. Sticker price will be equal or less than stateside to begin with, and factoring in additional sales tax in the states versus VAT refund for the exact same purchase in both countries, you will still save money. You're going to buy those items on your wish list anyway, buy them if/when you see them in Europe to save, whether a little or a lot.
All that speaking from firsthand experience with both Vienna and Prague btw
Look for Antonia or Sabine in Vienna, and Olga in Prague. If you decide to visit Salzburg, look for Marina. All ladies are helpful, polite and patient. Good luck and enjoy the H-unt!
