It is difficult to give a specific price for renting a flat in Istanbul, as the cost can vary significantly depending on several factors, such as location, size, and amenities. Generally, you can pay more to rent a flat in central Istanbul, while prices may be lower in more suburban or outlying areas.

One-bedroom flats in Istanbul can range from around 5.000 (300 USD) to 19,500 (1.000 USD) Turkish Lira (TL) per month, while two-bedroom apartments can cost between 800 (250 USD) and 2,500 TL (650 USD) per month. These prices are just estimates and will likely vary depending on the specific location and amenities of the flat.

It is an excellent idea to research and compare prices in different areas of the city to understand what you can expect to pay for a flat in Istanbul. Consider using a real estate agent or broker to help you find a suitable rental property, as they can provide valuable information and assistance.