"... accordingly, they cost more." I disagree with this. Contractors pay a significant price by leaving a full time job. No benefits, no company sponsored talks,training, no paid time off. The extra buck you make contracting is not extra.
The real price of contracting isn't the loss of benefits, but the increased burden of providing those things for yourself (if they were that important to you in the first place). The real reward is: freedom. You can provide any/all/none of those things for yourself as you see fit.
All presuming you have work, of course ;-)
My secret has been to do such a good job that the client finds me indispensable and then leave on my terms, always with another gig lined up. Sometimes I've had to stay with clients for many months when I'd rather move on. Once I was working for a client that had a smell like they were going broke so I had to ruthlessly extract myself before my contract was due to expire, but that proved to be a good decision as a few months later nobody was being paid and were suddenly out of work.
I worked in a permanent role for 6 years before contracting, and I doubt it would be a good idea to do it with no experience. My first contract was acquired through an agency, and probably 50% of my work is through an agency, the rest is word of mouth and doing more work for former clients.
Having said that, there's a general attitude from employers (at least everywhere I've worked) of "I'm paying this person £400 a day, they'd better be good."
I've been on both sides, and from the employers side you're definitely willing to cut staff a lot more slack than contractors (though that may be totally irrational).