Author here. The 254% figure comes from RAND Round 5.1. I built a Python pipeline on CMS HCRIS cost reports (FY2023, 3,193 hospitals) to compute cost-to-charge ratios by ownership type. The surprising finding: nonprofit hospitals have a median markup of 3.96x actual costs. All scripts are in the repo. Happy to discuss methodology.

Thank you for doing this analysis! I'd suggest adding some charts to better represent some of the issues you've found!