...and small time rental house in Copenhagen.
Roger Deakins shot "In Time" in HD and upscaled it to 4k afterwards.... did you notice?
The worst that could happen buying those would be that the fresnel lens isn't of high enough standart, or that the housing is cheaply made and falls apart over time. The tech behind the actual light is old school and hard to mess up.
But I would still prefer buying used Arri lights if available, they are build like tanks and will take a severe beating and still work.
Actually... if you want something like raw, but can live with the compromise of cheap lenses, and shooting on card in-camera, then the Eos M (the first one...) with Magic Lantern is the cheapest way to shoot raw. Have a look at the article here on the site.
You wont even get uncompressed from a 5D... it's 8 bit all the way, including if you install magiclantern, then it will still be 8 bit coming out of the camera.
Except.... the very first footage he shows doesnt look cinematic at all... its not particularly good looking on top of that.
Why is it that every new film maker thinks that it's the camera that makes things look cinematic? Others have already said a lot of it...
But OP, if your focus is completely camera, then what you will end up with is decent looking footage with a crappy story, crappy acting and no thought given to the production design of your film.
All those play a bigger part in ending up with something cinematic than what ever camera you use... and ofcourse lighting too.