Here in BC Canada the scales are left turned on even when Closed. It costs nothing and is relatively easy to weigh yourself.
It takes two passes to get the job done. First weigh the front then the combined followed by the rear.
The second pass just move to the right so that the right side misses the scale. Again weigh the Front then combined and last the Rear!
You just subtract the Left side only weight from the combined and You get the Right Side!
I have noticed people doing the exact same thing in the USA . Don't know if there is a charge down there!