I'm sure £20-£30K is a VERY high estimate. I would estimate £5-£8K, I paid roughly £7K and the training is more expensive here than in UK.
It will probably also be worth it in the long run, having "local" licenses.
You can still work while studying ATPL, find some cheap distance learning course, memorise all the answers and get it over with.
I never heard back from Mahi....