@moana35 You're not ruling out drama schools, you're ruling out drama schools that charge extra top-up fees. We said the same to our DS when he applied.GSA is very much a drama school - it is technically part of the University of Surrey for financial reasons, but it's not a university-style course, and for MT would be hard to beat in the eyes of the industry.
However, as others above have said,for MT you have other options that are the same fees as normal university and can access student finance. Look at Urdang, Bird, Royal Welsh, Central, LIPA, Leeds Conservatoire, Wilkes, Performers, Trinity Laban etc. All of these plus GSA will offer high contact hours, excellent training, professional showcase, Spotlight membership etc.
Depending on your DS' aspirations, be careful of the courses offered by actual universities like Winchester and Chichester. The training might be great, but if they don't offer the contact hours they won't be eligible for Spotlight.Think about agents too - look at grad profiles if you can and see how many MT students get representation at the end, and what kind of agents they are. As I said, it all depends on what your DS wants from it.
Performers take a lot of students, so they can make a lot of offers. Not everyone will accept their place. GSA take very few, but they offer throughout audition season and will not have offered all their places yet. Some people they offer to will also get offers elsewhere. They will still be able to offer places in Spring.
If you can have a look at some of the schools people have suggested above, I'm sure you'll find a few more your DS can apply to that won't cost any more than a normal university course.