I am a sole trader (with ABN) and provide virtual (offsite) administrative services for small and medium businesses in Australia. In short I work from a home office. To remain highly competitive and instead of setting and advertising a set hourly rate, I want to provide the option for clients to send their request for services with their nominated set budget to complete the service. I will reply with either acceptance of that price or place a higher bid to complete the service. The Client has the right to accept my higher bid or decline. This kind of bidding for skilled and unskilled services is now happening on many well known large sites. Am I breaking any laws (i.e. commercial law) or unfair trading practices by doing this? Obviously it can be done where there is a large group of freelancers bidding for a job but for a sole trader to be charging different rates for perhaps the same service to different clients. Is this unfair trading or simply a matter of lawful negotiation and agreement? Did some research to find the answer but can't find adequate answer. Any advice greatly appreciated. Thank you.