Before you go making any headphones purchases, consult this categorized buying guide and this GIANT IEM guide.
When you're looking at the second link, scroll to the bottom and find this chart. Scroll down the chart until you see a price you're willing to pay, then hit CTRL + F and type the name of the product in question. Read it's review, read the reviews of other similar headphones in it's price range, yada yada yada.