I need an MRI for my neck and back and I can't get insurance so how much will it cost for an MRI without insurance?

Shop around. Shop around, tell them the situation, and tell the places that you are cash paying and want a break. I can't give you prices, they fluctuate in different areas, and different parts of country. Even locally, there is price variation, and negotiable. Use one place against another if you have to.
Good? Hi, you need to call outpatient imaging centers (independent facilities) that are NOT affiliated with a hospital. That is where you will find the best prices. The center I work at charges $350 for an MRI whereas the hospital down the road charges around $2000. Call the facilities and if need be, look for some in nearby cities or states - I have people coming from Canada & neighboring states.