Find a quick cost overview here.
From working with home builders I have picked up a few things. One, you need to do a complete bid to know for sure what the cost will be. The codes in the City are stricter so make sure you have the needed space, follow all zoning requirements and obtain the necessary permits. Two, as a quick reference a rule of thumb I use is $10,000.00 a bay is a good guesstimate (a two car garage would then be around $20,000.00). However it can be much less or much more depending upon the materials used (vinyl is a lot cheaper then brick and you stated you want to use cement board which is a little less then brick, the type of roof, etc.). Insulation and drywall will also add to the cost so I would think you would be somewhere between $30,000.00 to $40,000.00 or more. With insulation and drywall it sounds like you may be considering finishing the interior of the garage at a later time. If you are, again be aware of all codes relating to this.
There are also websites that can estimate the cost for you but the best thing to do is to obtain bids from three or four good contractors.