The Collaborative International Dictionary of English v.0.48:
Costliness \Cost"li*ness\ (-l?-n?s), n. The quality of being costy; expensiveness; sumptuousness. [1913 Webster]WordNet (r) 3.0 (2006):
costliness n 1: the quality possessed by something with a great price or value [syn: costliness, dearness, preciousness]