PGCE or Masters whilst working - which is more demandingWatch
PGCE is a teaching qualification that is focussed more on teaching practice and the actual professional skills of teaching. The course is usually based on two assignments and is worth 60 CATs. A Masters is 180 CATs, usually. This is because the majority of your PGCE you will be working in school developing your pedagogy.
If you would like to be a teacher, I suggest the PGCE. You can then take the Masters at a later date and, generally, you can count your 60 level 7 CATs from your PGCE and use them to complete your Masters. So, you would only need to complete 120 CATs for your Masters, saving you money and time!
I would stress to you - the MA is not a teaching qualification and will not teach you how to teach. It is aimed at those who want to develop their practice in other ways. You will make the most of the Masters research dissertation if you are already working as a teacher at that point. It would make a lot more sense to go through the PGCE.
Edit: PGCE is 4x the price because you will get an internationally recognised teaching qualification. For example, you could not practice as a qualified teacher in the UK with a Masters in Education, without a BEd or PGCE that gives you QTS (Qualified Teacher Status).
Hope that helps and feel free to ask me any further questions.
Hope this helps