What happens when your assignment ends? Are you an employee of Kforce or the actual company that won whatever contract they are trying to staff to? That should also be a consideration, IMO because I would imagine you don’t want to join a company only to be off contract in six months to a year. That may also be why the job offer is less than you were expecting — they were probably the lowest bidder (or your labor category is lower due to lack of four year degree — I’m in defense contracting and I see this all the time).
I agree though that this is a chance to get back in the workforce, continue to gain experience, get health coverage and benefits while continuing to look. It’s always easier to look while employed than not and who knows, you may meet someone who knows someone who has a need for your skillset…
Then again, the six week assignment you just took might also pay off… at least you now have options!
Good luck however you decide.