To make this decision you may need to know more about the business logic of the owner, but I would be inclined to think that having it all together in one Laravel can be very cost-effective in terms of effort, since if you have to do an update (of the Laravel framework or a third party library) you will only do it once, or if you have to implement a new functionality (like defining a new middleware) you will implement it in the whole application at once.
The downside is that if you need to have different logic for the same parts of the application it could be a nightmare, for example different password policies for courses and shop.