There's not much that's actually changed in an electric car service (there's no engine oil, for example) so EV servicing is usually cheaper than servicing a petrol car. You'll still need to get the car serviced regularly to avoid invalidating the warranty, although you might find a local garage willing to do it for less. That said, those prices don't sound unreasonable and you'll have the peace of mind of having your car checked regularly by a main dealer.