Direct contact
The benefit to you as a customer when hiring a freelancer is first and foremost that you get direct contact with the translator. You can call or email the person who does the work directly, without a project leader as the middle man. That makes it easier to ask questions, send extra material or discuss the text. If you hire a translation bureau you usually do not get to talk directly with the translator.
We can also get to know each other in a different way compared to if you work with a bureau. You will know who performs the work and I get to know who you are and learn how you want a text to look.
The price
Another advantage is a lower price. A freelancer usually does not have any employees, no expensive offices, no reception or telephone exchange. This means that the costs can be kept down and the price for the translation will be lower for you.