The Centrios ones aren't that expensive, but watch out for thin cords. Usually earbuds that go in-ear or are canalphones, tend to have noise travel up the cords like you're wearing a stethoscope. That's one of the reasons why Shure earbuds have such thick wires.
If you can afford them, the best in-ear/canalphones are from Etymotic Research and Shure. They're expensive, but the sound quality and the construction quality makes it all worth it.