How to shop for speakers<br>Decide how you'll use the speakers. The variety of speaker builds suits individual speakers for different tasks. For casual music listening, a pair of bookshelf speakers would be more than enough.
For causal music, you need the best speakers in the market. 
according to the text,  for casual music listening, a pair of bookshelf speakers would be more than enough, which means a regular price speakers is enough. 
( z1 need :ARG0 ( z2 you ) :ARG1 ( z3 person :ARG0-of ( z4 speak ) :ARG1-of ( z5 have-degree :ARG2 ( z6 good :ARG1 z3 ) :ARG3 ( z7 most ) :ARG5 ( z8 market ) ) ) :purpose ( z9 music :mod ( z10 causal ) ) )