If you're a thrifty spender, your best bet is this Lydell NYC Pendant. It's a wonderful piece, while not very costly. In this price range, you can also check out this Gurhan Pendant. It's also a popular item and won't break the bank. You might also want to consider this Judith Ripka Pendant. The price is very reasonable, but the effect on your wardrobe will be pretty fantastic.
If you're looking at it like an investment piece, then you absolutely must check out this Konstantino Pendant. This piece seems expensive, but it's top quality. Why not take a look at this Roberto Coin Pendant too? Expensive, but worth every penny. And one more item you might be interested in is this Ippolita Pendant. 'Cause you deserve nothing but all the finer things!