Maybe in the short term, but ultimately companies make profit when there are lots of consumers with the resources to buy their product. Squeezing employees makes them unable to consume as much, which slows the economy. Ten thousand people buying a $300 TV makes the company way more profit than ten millionaires buying a $30,000 TV.
GDP is a bumpy measure that tries to sum up a lot of complexity in one number, but over time (years) it grows faster when the middle class does well.
The cost isn't the cam itself, it's the servers and their software and IT administrators to maintain them, the personnel to audit the videos, and the personnel to respond to records requests by being able to locate archived files and redeact private information of the people the police interact with in the requested videos. Spinning up and maintaining multiple departments that just didn't exist before a body cam program was implemented is a significant resource draw.
If the auditing personnel aren't hired in sufficient numbers, or the IT personnel to keep the video archives actually usable, then turning off of bodycams won't ever be caught.