I am employed as a Real Estate Agent and am paid solely by commission. I can go weeks and sometimes months without payment. When I am paid commission it is usually between $1000 and $2000.

However, one year I earned only $15,000 gross which is less than the minimum wage of $280 per week. Is my employer obliged to top up my pay in any week where I earn less than $280?

The Minimum Wage Act applies only to employees. Most Real Estate Agents are not employees, but are independent contractors.

An independent contractor is someone who is genuinely in business on his or her own account, whereas an employee is not.

To determine whether you are an employee or an independent contractor, you need to look at your contract with your Real Estate firm. Most contracts will state how you are engaged.

You have mentioned in your letter that you "incur daily expenses". This suggests that you are an independent contractor as an employee has no ability to deduct expenses from his or her gross pay for tax purposes.

See Also
Current Minimum Wage