Yes, plastic is expensive.
Case guards and frame sliders for the Bandit will help to prevent plastic damage in a parking lot tip over - as long as you don't punch a blinker thru the fairing. They aren't likely to save the plastic in a spill at road speeds . . . they'd have to stick out past the blinkers to do that. (Hard bags, like Givi, have been known to save bikes at speed - at the cost of a hard bag.) What they should do is keep the engine from being cracked or ground open and spilling it's blood all over the tarmac, allowing you to ride your bike away from an incident.
Engines are more expensive than plastic.
Best thing is not to drop your bike.