You asked
Should I upgrade from the panasonic lumix bgh1?
It depends on what you're missing. The BGH1 is a box camera for video rigs and live production, with no screen or viewfinder and no stabilisation in the body. If you shoot stills and need to frame and review your shots, that's the big gap, and upgrading makes sense.
If you're keeping it for its job, a stabilised lens helps with slow shutter speeds. Two I'd look at from the BGH1 lens list are:
The site doesn't compare camera bodies yet. If you do upgrade, buying used is a good way to get a newer body for less, and sensor sizes explains how sensor size changes the framing you get from your lenses.
Written by Claude from this site's pages.