These are excellent responses as usual, and I'm coming to this a few days late, but I wanted to add another answer for someone who maybe isn't willing to bite off quite as much sales skills as tptacek and patio11 are suggesting, or are dealing with a buyer who doesn't have the authority to go against the agency rule - i.e. the dev manager wants to bring you in, but he has no idea who he has to talk with to get you on board as an independent contractor, and you're not on an approved list, and two people tell him that he can't do it, and three months are going to go by and meanwhile everyone is frustrated, including you, who wants to work.

This is a common, real-world scenario, and we see it all the time. Agencies, in fact, are used to it: it's called payrolling.

If you find the work yourself - i.e. someone wants to hire _you_ but needs you to go through an agency - then ask for the names of three agencies they work with, and if any of them payroll. (They may not know the answer to that.)

Then call all three, tell them the hiring manager and anything else you know about the financials (you might know bill rate, or what you want to make, or both), and tell them you're calling all three agencies, and you'll go with the one that can make the best deal. That's a win for the agency (a little money and another person on the books with that client) and a win for you (in comparison to the $65/$130 deal). Factoring in things like employment taxes and such, you can assume that you'll keep ~90% of the bill rate. (So $65 would become $117 total comp: if they're required to employ you and pay taxes, offer insurance, etc., more like $95 to you. Look, almost a 50% raise.)

We're a small agency (~50 engineers), and we usually have 3-5 people we're payrolling because either the client called us and asked us to payroll, or we got a call like the one above and decided it was worth it.