Both Cruden Bay and Crail rent power-trolleys. Not sure of the make - Powakaddy, I think. Cost IIRC, was 15pounds for the day, which was reasonable, for UK pricing.
I found them ideal, since at that time, I had to use a pull/pushcart because of back problems.
Last summer, I advance booked electric trollies at Cruden Bay, Royal Dornoch, Brora and Boat of Garten They were about 10 pounds each place.
In addition I had pull trollies at Nairn Dunbar, Nairn GC, Lundin and both New and Jubilee at St. Andrews. One of our two rounds at the Old was in the evening with a local and I got a trolley for that, as well. They were usually 3 pounds IIRC.
As for the U.S., my home club has a fleet of Bag Boy rental three wheelers, and charges $2 per round.
I have also rented both three wheelers and Riksha two-wheel pushcarts in Arizona and never paid more than $5 for one .
Given the difference in overhead between a pushcart and a riding cart--in the form of initial cost, maintenance, cart storage, fuel/electricity, cart-staff wages, insurance, and even the cost of cart paths and turf repair--I can't see how someone can justify charging anything close to the same price for them.
A pushcart costs a little over $100, and has minimal ongoing cost.
If you subtract the cost of owning, operating, storing, maintaining, and managing a riding cart fleet from the gross reciepts, how much is left per player per round? It might be 10 bucks, but I'd be surprised.
Heck, at my club, there are still people who think the F&B operation makes money because all they charge against the gross F&B reciepts is labor and materials--completely ignoring the long-term and recurring costs of the facilities used by F&B.
K