Search new + high quality used tires online. Size 315 30 R21 starting at: $60.48. Tires in stock: 100. Available brands: 4 with 19 models. All season: 36. Winter: 7. Summer: 57.. Selling all used tires at discount costs. All used tires go through 2 layers of inspection on specialized equipment. One year warranty + free shipping on all inventory ;) Happy shopping!