Adjusting the 40/40/20 Rule for Key Camera Features (e.g., Internal RAW, Full Frame)

Hey fellow cinematographers, I'm Sarah Chen, and I'm wrestling a bit with budgeting for an upcoming project, a smaller-scale narrative film, aiming for a very specific look. We're leaning heavily towards a full-frame sensor and internal RAW recording, like what you’d get from an ALEXA 35 or even a LUMIX S1H. My usual approach follows the 40/40/20 rule (acquisition, crew, post), but I'm finding that prioritizing something like internal RAW on a camera that isn't a rental house staple or a full-frame sensor often pushes the acquisition costs significantly higher than 40%.

I’ve tried balancing this by looking at more affordable lighting, perhaps swapping an Orbiter for an LS 600d Pro and a couple of amaran 150c lights, or even considering different audio packages, but it feels like a forced compromise elsewhere. My worry is that if I allocate, say, 50-55% to acquisition to get that camera, I’m severely shortchanging either crew or post, which feels unsustainable. How do you all adjust this classic budget breakdown when a specific, non-negotiable camera feature dictates a higher initial spend? Does the 40/40/20 fundamentally shift, or do you find ways to recoup that elsewhere without impacting quality?

Thanks in advance for any insights!