Hmm… I pay up to 26 cents per thousand Watt hours of electricity, and my bathroom uses a mains powered 10 Watt LED bulb. Now let’s say a bathroom visit is 5 minutes. For 26 cents I get 1000 kWh, or 100 hours of mains powered bathroom light:
At 5 minutes a visit, I get 1200 visits for 26¢.
So, please, please do tell us about all the money we will save by spending $40 on a toilet bowl night light 
In just 184,615 nighttime trips to the bathroom (very roughly, about 200 years worth) I can make my money back! (Not including cost of replacement batteries… :-/ )
