the diamond convention is nothing more than a clever bit of marketing by deBeers.
SOOOO0 true! Diamonds are actually MORE COMMON than the amythest!

DH wanted to get me a diamond at one stage - I told him that I dont want to be just as special as everyone else.

I have a lovely yellow sapphire that takes everyone's breath away.

As far as the cost is concerned - can you put a price on love? Does it really matter if it cost $100 or $10,000? Who cares for the cost - it is what it means that is the important part.