Well,

If I take off the 15 days vacation, I would still be over $10k for a contractor than an employee. It's a small start-up, I do not think they do 401K match. As for bonus, I am not sure if they would give $10K for a software engineer position. What are the other benefit I miss(I do not need the health insurance). As to job security, all the job is not safe, right?