They strongly advise you to take the IELTS instead of using documents to prove your English unless English is your mother tongue. If you use documents, you are putting it in the hands of the visa officer how many points they give you. Some, none, who knows, maybe not enough for your application to go forward.
Therefore, if it's at all possible for you to take IELTS, do it. Time and money is not a good excuse when it's put up against having a successful application.
Go to http://www.cic.gc.ca/english/information/applications/skilled.asp
and read the application guide for Federal Skilled worker and you will see how many points you can get for English depending on your score on IELTS.
You can in fact apply without IELTS but if they accept you and give you 120 days to send your documents, you would have to take it. When you take it, it also takes time to schedule the test etc., you may have one chance to take it and wait for your results in the 120 day period and then what happens if you do not get as many points as you thought and end up with less than 67? We see people come to this board in that exact situation all the time. Better to take the IELTS before and be sure that you have 67 points before you apply.