Staples offers the Expo Chisel Tip Dry-Erase Markers 4-Pack in Black, model no. 83661, for $4. Plus, Staples Rewards members bag free shipping. (Not a member? It's free to join.) That's the lowest total price we could find by $4, outside of the mention below. They feature chisel tips.
A close price: Walmart offers these for $4.37 via in-store pickup.