If you're looking for a low-end pair of earbuds that are durable and will give you excellent sound for the money, the Sony Fontopia MDR-E818LP are the best deal out there. I've tried several sets of earbuds and none of them stood up to the Sony Fontopia.
I originally bought these earbuds for use with brainwave entrainment cds, which require headphones with excellent frequency response to work properly. I was a little worried that inexpensive headphones would not give me the same effect I'd been getting with well positioned speakers, but it turned out they actually worked better.
These earbuds are also fairly comfortable and good for someone with small ears. They're almost comfortable enough to sleep in with a little pillow adjustment. They stay in the ears well, even when exercising. They're not perfect, and if I wear them for a very long time my ears will get a little sore, but I'm yet to find any low end earbuds that are a better fit.
After about a year of hard use, they're still working great. Most of the others I tried lost sound in one ear or the other within a few months or had a hollow unsatisfying sound quality. The Sony Fontopia sounded great from the start and are still working well.