CMA takes around 6 months to get prepared. There are two parts to the exam. Compared to other courses in the financial field, I believe CMA is the best in terms of cost as well as duration. If you are a commerce student, its going to really help you get a high paying job in the future. Not that just a course can help you land a great job but I believe the amount of knowledge that you get when you do certifications like these can broaden your horizons. It definitely worked for me when I did CMA in the last year of under graduation (B.Com). I did get paid a lot more than my friends who just had the undergraduate degree. Then I went on to do CA and CPA.
I took my training from CPA Course and CMA course in Hyderabad|Simandhar Education| and they were pretty good about helping me out right through the process. I was able to finish my course and clear the exam in about 6.5 months to be precise. Good Luck!