Hi there,
I'm awaiting the award.
I followed the E801 course with the open university. The AMBDA bit is 'extra' but linked with it and is linked to Bangor.
It costs roughly £1200 for the OU course and about £470 for the AMBDA bit. There is a certain level of discount for serving teachers.
It has been hard work, but worth every ounce of sweat! I was fortunate to get TDA funding last year.
I have also spent quite a bit (don't go there, over 1K) on the assessment resources necessary. However, I intend to go private in addition to my current work in schools.
Go for it. It has been a life changer and I would say my practice in schools has improved exponentially as well as my ability to narrow down what children really need via assessment as part of an evaluation of needs.
I believe the OU courses start imminently.
Otherwise, it may be worth having a look for accredited courses via the BDA site.
Good luck.