need or not

umm..
talkin bout english course.
do i need it or not ?

well i know i'm not good in english especially in vocab
'the worst part of my english is all about vocab huff.'
but there's a consideration that makes me confused
if i need to take the course or not
my sist told my mom that my english is ok
but i only need to 'practice'
'practice' means ..
hear some english songs,
learn to sing it with the right pronounciation,
read some english book,
or many things that can makes me get so many new vocab

cos of that, i started thinkin twice to take it
my consideration are:
1. i wanna go for conversation class, but there's only in sat for 3 hours & most of them are the workers
2. i do need english course, but if i just need to 'practice', i can do it just via internet 'n hear some songs in english
3. it's a bit expensive 'n not all of the courses are good

so my question ...
do i need this course or not ??

p.s. for me, it's better to have a convo class with de native teacher than with de indonesian teacher ! but it's very expensive ~~