Congratulations Bex! My twins who are nearly two were born in the American Hospital. Because you have a twin pregnancy you are automatically high risk, so I really wouldn't even consider delivering here without any insurance. Mine were born at 32 weeks and spent 10 days in NICU at a cost of almost 150,000 AED. Thankfully our insurance covered most of it.
There is a very active multiples group on Facebook called Twinsplus, and lots of advice from Mum's of multiples on there.
All the best for a healthy pregnancy.