Is there a good comparable headphone to Koss's "The Plug" Headphones?

Normal in-ear headphones don't fit my ears very well at all, especially if I am wearing them while running or something, they always fall out. "The Plug" headphones work great because you smoosh them like foam earplugs and put them in your ear and then they expand and form to your ear, not only making a perfect fit but also blocking out noise. The only thing is they are relatively cheap ( you can find them for around $10 ) and I was wanting to get ones that fit the same but are a higher sound quality headphone.