The reality is that the LAPL probably won't be any cheaper to obtain.
Anyone who thinks they can just cut 15 hours from the syllabus and still pass what is basically the same test to the same standards is kidding themselves. If you put the LAPL and the full EASA PPL syllabus next to each other, they've literally just cut 10 minutes from each lesson without actually changing the content of the lesson. There's no way that people will regularly go through this course in 30 hours and come out at a high standard, most struggle to do it in 45.
So if you have any hope of becoming an instructor in the future, I would just do the full PPL from the onset, as you are then not restricted in what aircraft you fly, and to get on the instructor course you will need at least 200 hours anyway.