How many letters does the top answer for “the quality possessed by something that is excessively expensive” have?

The most common answer is sumptuosity (11 letters).

Crossword clue: the quality possessed by something that is excessively expensive

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

sumptuosity 11 letters wn-def

the quality possessed by something that is excessively expensive

sumptuousness 13 letters wn-def

the quality possessed by something that is excessively expensive

the quality possessed by something that is unreal 50% similar → unreality