take what you can afford to live on, and continue to perfect your craft. finding out the common wage for a 3d artist and hard lining your employer may backfire. Add up your bills, your food, ect... add a fun time 100 dollar bill and do get moving on the project...
Im currently freelancing and my employer is in the same geographic area as me, so they understand the cost of living, and basically, its that... as a freelance artist starting out, you better be happy doing what you you are doing. because from what ive seen, especially lately, I cant seem to find a way to stroll straight into 7k a month like in the IT business where I came from... but then, its not really about the money to me. I work twice as hard and about 1/3 more hours for almost half the price, but I couldnt be happier.
having said all that, if your contracted service is indeed equal to the hired counterpart.... a contracted service should net like 15-20 % more than a hired drone typically, due to insurance, benefits ect depending... at least it was like that installing networks and PCs.