Amazon offers Prime members the Sharpie Assorted Colors Ultra-Fine Point Permanent Marker 24-Pack, model no. 75847, for $10 with free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping costs $6.10.) That's the lowest total price we could find by $4, outside of the mention below. These markers feature nontoxic ink, which is waterproof, smear-proof, and fade-resistant.