Tanga offers the HBQ i7 Twins True Wireless Earphones with Charging Dock in several colors (Black pictured) for $29.99 with free shipping. (4HotSeason via eBay charges a few cents more.) That's the lowest price we could find by $2. They feature 4-5 hours of play time, hands-free calling, and lag-free connections.

Note: As we listed before, they're also available without the charging dock for $19.99 with free shipping.