Costly rhymes with:
costley, costley, astley, costley, dishonestly, earnestly, firstly, ghastly, ghostly, honestly, justly, lastly, manifestly, modestly, mostly, priestley, priestly, robustly, steadfastly, unjustly, vastly, westley
Costly sounds like:
caddell, cadell, cadle, cadwell, casteel, castel, castell, castellaw, castelli, castello, castelo, castilla, castille, castillo, castle, catelli, cathell, cattell, cattle, caudal, caudell, caudill, caudillo, caudle, cedillo, chadel, chadli, chadwell, chattel, chatwal, cheadle, cheetal, chikatilo, chotilla, citadel, coastal, coattail, cocktail, coddle, cogdell, cogdill, costella, costello, costilla, costilow, costley, costlow, cotelle, cotilla, cottle, cuddle, cuddly, custodial, cutillo