Work permits are $150. However you should know that it's quite difficult to qualify for a work permit.
In order to qualify to apply for a work permit, you must first find an employer who is willing to offer you a job. That employer must then obtain an approved Labour Market Opinion (LMO). As part of this process, the employer must advertise the job and prove that they could not find any Canadians to hire for the role. If the LMO is approved (not all are), you can then apply for a work permit. If the work permit is approved, you can then start working.
You should be aware that many/most employers aren't willing to go through the LMO process and for this reason aren't willing to hire foreign workers. So finding an employer who wants to hire you will probably be very difficult if you don't have specialized skills, education or experience.