An H1B immigrant worker in IT industry [consultant] is placed on projects at various "client" locations. E.g. CitiGroup. They are placed through staffing agencies [vendor] that as commission cut out an '"undisclosed" amount as commission. This paper trail needs to be made transparent to the consultant. The consultant is paid $30/hr. But I have seen the client writing $117/hr requirements documents for the work done.
Also these clients' rarely are ready to provide any documentation that says the said consultant works onsite! They are afraid they will have to pay benefits.
The consultant pays his health insurance out of pocket, his visa application fees, any query for addl information on these visa application is paid for by the consultant. No pay is given when they are between projects.