Fiord Beauty via eBay offers the Sally Hansen Miracle Gel Nail Polish in several colors (Tribal Sun pictured) for $4.74. Add three to cart for a price of $9.48. With free shipping, that's $3.16 per bottle and the lowest price we could find for the quantity by $5, excluding the below mention and other eBay vendors. (For further comparison, shopping in-store, most retailers charge between $6 and $7 per bottle, depending on color.)

Want a different color? A1greatdealstore via eBay offers 3-packs in several additional colors, with prices starting at $9.90 with free shipping. (Add three bottles to cart to see this price.)