1. the quality or state of being expensive or high in price
2. the quality of being precious, valuable, or of high worth
3. the quality of involving great loss, sacrifice, or suffering

Examples

• The costliness of the renovation project surprised the homeowners.
• She appreciated the costliness of the antique vase her grandmother left her.
• The costliness of the war in lives and resources was devastating.
• Despite the costliness of organic produce, many families choose to buy it.
• The costliness of his mistake became apparent only later.
• Luxury brands emphasize the costliness and exclusivity of their products.