Costly and First-class

Costly adjective - Commanding a large price.

First-class and costly are semantically related. In some cases you can use "First-class" instead an adjective "Costly".

Nearby Words: cost, costless, costliness

First-class adjective - Of the very best kind.

Costly and first-class are semantically related. Sometimes you can use "Costly" instead an adjective phrase "First-class".