Hi there,
A very good question. There is very little readily available information on salary ranges and there are lots of examples of people doing the same job with very different salaries.
With out knowing the details I would say that for a trade representative with about 1-2 years experience you should be looking at around 700 USD - 1000 USD. Obviously this is going to depend on the role requirements.
If you can let me know more details I will see what I can do to help.
Regards,
Thomas