I use elance/odesk extensively. My biggest pain point is trying to figure out the real rates charged for work. What would be perfect is to give each freelance

I use elance/odesk extensively. My biggest pain point is trying to figure out the real rates charged for work. What would be perfect is to give each freelancer a 1-2 hour test that will be shown on their profile. It will show what they are capable of within 1-2 hours. For example, a logo design. Each applicant does the same test.