When sourcing denim, the price is primarily driven by fabric weight (measured in ounces/oz), composition, and wash techniques. Lightweight denim (under 12oz) is cheaper but less durable, while heavyweight denim (14oz and above) commands a premium. Ensure the composition meets your needs, such as 100% cotton for authentic feel or Cotton-Spandex blends (2-3%) for stretch comfort. Additionally, check the yarn-dyeing method (e.g., rope dyeing vs. slasher dyeing), as rope dyeing typically results in better color fading and higher market value.