I always have a fascination for something unique and stylish. Look at how they made use of those square vases and clear vases as candle holders and fresh flower vases! So elegant and stylish! I never thought of this idea which I think is really cool and "eye catcher". It would definitely add a "drama" and romantic atmosphere in your dining area.
Of course when choosing the glass vases, we have to choose those "durable" ones. We have to invest on something which is of good quality. Square vases at www.potterybarn.com is quite costly but perhaps would certainly last for years. But if you're on a budget, you can choose from the shops around your area. At any rate, since you'll definitely like your dining area to stand out, it would be wise to invest on something of good "quality". You will save in the long run.
I feel like want to try it! :)