Costles or Costless: How To spell?
The word Costles is misspelled against Costless, an adjective meaning "Costing nothing."
Costless has double 'ss' in the end mispronounced as 's'Remember double 'SS' appears in the end of this word which should not be misspelled with single 'S'
Wrong Spelling:  costle-s  Correct Spelling:  costle-ss 
Find more incorrect spellings of Costless to spell right way.