高価

1. Origins, structure, and basic meaning

• Structure: 高価 is read as こうか and functions as a な-adjective or noun for something expensive or high in monetary value.
• Basic usage: Predication appears in 花瓶は高価だ, while noun modification appears in 高価な工具.

2. Common pitfalls and similar expressions

• Difference from 高い
  • 高い broadly means high in price, height, or degree; 高価 is limited to high price or monetary value.
• Inflection pattern
  • Use 高価な before a noun and 高価だ as a predicate; it does not inflect as an い-adjective.