I own a policy from IMEDI, their Premium Plan A is quit alright. However, I have recently found that the Vienna Group might offer better plans: www.gpih.ge. As an expat, you could also consider some international insurers--usually in the UK--who over overseas coverage for any nationality: the price might be USD 150 per month, but I've heard the coverage features are very goo.
Prices will vary based on the plan, mine cost about USD 200 per annum. I reckon you could get basic coverage for as low as USD 50 per annum from the Vienna Group.
I just realised you used the word "tourist" in your message: that might make things a bit different. As a tourist, you probably can purchase from the international global travel insurers like IMG. I bought really goo travel insurance from IMG at very reasonable prices depending on the limit and the duration of travel.