I too say the methodology is flawed. The instate rate for tuition plus room and board at LSU and UMD is nearly identical and yet MD is 6 and LA is 32. Sure the avg salary is higher in MD but housing costs are much higher. Tulane is the only substantial private school in LA to drive up costs and Tulane is generous with merit aid compared to most privates.
UMD also has far less merit aid. LA’s TOPS program is in financial trouble and created issues but has made tuition affordable. Part of the problem was substantial “merit aid” is given to ACT’s in low 20’s.