I like to detail too but detailing a car is not the same as repairing headlights either. Then again sometimes you need to say, who cares.
I will play the other side (you know me). People pay how much for the car and then headlight price is an issue? That is like buying a home and then trying and DIY a subpanel breaker box or try and clean a hot water tank....
But, ya if you have an older car and not worth much, sure it is worth it to clean. Since the lights might be same value as the car.
Your light problem is a little, well, over extreme since if you need to replace all the lights in your Lexus, or any car, get another car.
Plus you know that $1,100 WHOLESALE is now $2500 to your door?
Then gain I do not maintain my headlights and they look new (except for the chips from trucks).:)
Again, you know me.