Depends on how well you listen to instruction and that you also help yourself upgrade by doing jobs, farming an inactive. Help yourself more, the quicker you'll upgrade. Once you've got 1.5mill find yourself a volley partner preferably in your club who can volley that person with you and take them further once gone to your limit. Make sure they understand what they need to do to get 12 dorms with tier 2 crew. Your volley partner if more experienced can tell you in further detail or look to one of the wonderful guides on these forums. If you are aiming for 10kcs stats you should aim to have double the amount you need to upgrade before you do so - this means you still have money to volley with. When you move onto tier 3 I would save up to 330mill so you can upgrade someone fully to 5kcs. When you do upgrade, let your pupil know.
I think I got 10k cs within a month of playing, and I got the stats I have now by the end of March, when I started on Jan 14th. That's without getting the starting volley, and maybe 3 small vollies around feb/march. Everything earned on my own.
You can get 20k cs in one day. Just need to find the right person to help you. They also need to know the technique.