for a tax number you need to go to the tax office which is a large white building to the side of migros

Hi louisa
tax number no problems and free . heres a rough guide to prices in Turkey so you can compare.
400 ytl gets you in patient care for one year. This depends on your age but I never ask a lady that....
1800 ytl is full cover for doctors and medicines etc +hospital.
Its better to have the in patient one and pay as you go for medicines as they are not expensive.
These are guide prices, if you are young then it will be cheaper.

Louisa Yapi Kredi bank do a good health insurance cover ( my experience) and they are certainly cheaper than BUPA.