Originally Posted by
ISTFlyer
Are you speaking of the arrivals duty free store that is located in the baggage claim hall?
If so, you could clear immigration if you fill out the passenger locator form and have a negative COVID-19 PCR test which meets Turkey's entry requirements and shop at the arrivals level duty free.
There are no extra COVID related checks so a 3 hour layover should be fine depending on the immigration wait times.
However, be aware that you wouldn't be able to take liquids over 100mL ( alcohol, perfumes ) onboard to your onward flight to VIE unless they are in a sealed bag. Obviously, you could check a carry-on at IST at the regular check-in counter which might be your getaway if there are issues regarding taking liquids onboard to your connecting flight.
Correct, arrival duty free. Aiming for cigarettes as they are 30% cheaper in arrival hall than those duty free shops. I will exit airport as usual (instead of transit I clear immigration, shop at duty free and return with printed boarding pass to clear immigration again).