I don’t know about CS, but I did research a lot of Midwest schools looking for low prices. Missouri seemed to have the most options for us under $15K with automatic merit. SEMO, NWMSU, MO West, MO State, Central MO…DD’19 went to Northwest Missouri State which is public but a nice size of about 6000.
Check out their Northwest Promise on this link which covers tuition if you meet the income and academic guidelines:
R&B on campus runs about $10K but can be much cheaper off campus after freshman year. DD '19 was able to cover a lot of her costs with savings and work.