Counter balanced bed

I started to wonder if bed heightening would be a better solution to fix.
-The good quality T8 rods are expensive
-Bed height movement is slow
-The need of two motors

How about using belt driven bed with balancing weight (like in the elevator mechanics)?
The counter weight (equal with the bed) moves on the back of the frame up-down. The motor does need to lift just a weight of the object (or the half if counter weigh would be over size) as the counter weight balance the system.

The sec