If you would use 35mm cine film stock that could work, because that has a clear base as opposed to the orange base of still film. It is normal to make a projectable 'print' from the camera negative. You would not be saving money though. Also consider that with a negative process you are developing twice, as opposed to once with slides.
In my case, I was trying to get quick positives from b+w negs to use in a slide presentation without having to first make a print and then photograph that.
Before I had a color printer I once shot a series of photoshopped images off the screen on color film and then had them printed large for a presentation. It was low res, but they had a nice glossy glow to them.
There were all kinds of hoops to jump through before everything was digital.