The Tax Audit Part 9 - Going to Tax Court

Going to Tax Court is not expensive or complicated.  You do not need a lawyer or even an accountant.  That said unless you are well versed in Tax Law and researching jurisprudence I would at minimum hire someone to research the arguments needed for Court, and to help you prepare.  If you want to represent yourself, you can, again I would suggest taking a professional with you.  CRA has lawyers from the Justice Department to represent them why would you go up against a lawyer by yourself.
To be successful in Court you will have to show solid reasoning as to why the CRA erred in the re-assessment.  You will need to quote Tax legislation that supports your position and quote Court cases that have been heard around your issue or similar issues.  Going into Court and saying CRA are wrong because I said so will not get you very far.
There are two processes you can choose from for Tax Court.  The first is called the Informal Procedure and is for amounts in dispute of up to $12,000.  The other process is called the General Procedure and is for disputed amounts in excess of $12,000.  Issue complexity has nothing to do which one you choose.  Decisions heard under the Informal Procedure are not precedent setting, while decisions heard under the General Procedure are precedent setting.
There is no real difference to you.  A lawyer or accountant are not required for either, but as stated above, it is probably a good idea to have one or the other with you.
Another tip I can give you is to go to the Tax Court of Canada website and read some of the Court cases.  Find ones that have the same issue as you are dealing with and see how others have done.  Pay special attention to the arguments made and the facts of the case.  Just because someone else was successful, or failed does not mean you will have the same result.  Each case is unique and has a unique set of circumstances. 
Good luck, and remember when in doubt get help.  A professional can be the difference between success and defeat.