Dagizmogeeks via eBay offers these Sony In-Ear Stereo Headphones in Red, model no. MDR-EX10LP, for $7.99 with free shipping. Aside from the mention below, that's the lowest total price we could find by $2, although we saw a refurbished pair for $0 after rebate in February. They feature 9mm drivers and neodymium magnets.

A close price: Bopo via Amazon has these headphones in blue for $8.75 with free shipping for Prime members