It’s a bit different here in the UK. In the USA you can do a very long presentation and tell people the price at the end to get sign ups. However in the UK people need to know the price first or they won’t listen to a word you have to say.
I think a combination of what you say above- give them the options by email first and then see on a discovery call what is the best option. For my fitness business I charge for the discovery call and if you come on board I deduct that from your first bill. However they are told of all my training options in advance.
If they have paid for a call and they know the options it’s a sure fire thing they’ll sign up to something.