What I have noticed at jewelry stores where I shop is that merchandise is ALWAYS displayed in a locked showcase, and the price/information tags are ALWAYS displayed with the price down.
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Yes, that seems to be the 'traditional' way (not much experience here - my wife is not into jewelry) but two stores I have been impressed with: one large, very exclusive establishment in Bal Harbour Shops in Miami that had a tiny, 3D price 'cube' next to EVERY item in their showcases - from a $120 charm to a $156,000 ring. The price tags didn't seem to hinder interaction between the customers and the sales people; they just defined the sales target.
The other shop I will never forget.
It was the main jewelry shop at the Ritz-Carlton in Hawaii (forgot which island). I had taken my very young daughter with me on a business trip and she wanted to buy "a dolphin pin" as a souvenir. We were the only guests in the shop. My daughter asked the very elegant, very pleasant, very friendly saleswoman if she could see a pin she spied in the back row of a showcase. "Of course!" was the immediate answer. The woman took my daughter's hand and I went off to look at wrist watches. I could see that the woman had attached the pin to my daughters sweatshirt and the two of them were admiring it and trying it on at various angles. Then I heard the woman say, "I have another pin here that you might like a little better because it really looks a lot more like a dolphin." They went over to another case and she let my daughter try on another pin. My daughter loved it! "Dad! Can have this one???" Pin was purchased. Just before we left the store, I remembered to ask the saleswoman why my daughter had finally purchased this pin and not the one she had first looked at and played with? She replied: "I knew exactly what she was looking for and explained to her why it was the correct piece of jewelry for her, at her age (she was 7 years old at the time)." Not once did the woman mention that the discrete tag on the pin she had been 'demonstrating' to my daughter (which I hadn't bothered to look at) showed a price of $85,900. 
S-m-o-o-t-h......
(I love this story. Sorry.
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I have always expected the reason for not displaying the price "UP" is that first, they want for the customer to fall in love with the piece before they realize it's out of their price range and second they want their salesperson to interact with the customer in revealing the price and perhaps selling the piece to the customer even though they can't afford it.
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In over 30 years of doing research (focus groups, interviews, etc.) for all kinds of retail businesses, we have found that this is a fallacy. "Old school", small retailers still think this way. Go to a large metropolitan Mercedes dealership and you'll see a price on every vehicle.>>>
People use credit cards everyday to buys items they can't afford.
No "stickers" on knives at shows for me please.